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Provide tags and a correct Python 3 solution for this coding contest problem. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum.
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Tags: constructive algorithms, graphs, implementation Correct Solution: ``` import sys n = int(input()) a=[] for i in range(n): a.append([j for j in input()]) b=[] for i in range(n): b.append({}) for j in a[i]: if j in b[i]: print('NO') sys.exit() b[i][j]=1 c=[-1 for i in range(26)] d=[-1 for i in range(26)] e=[0 for i in range(26)] for word in a: l=ord(word[0])-97 e[l]=1 for ch in word[1:]: ch1 = ord(ch)-97 e[ch1]=1 if c[l]==-1: c[l]=ch1 elif c[l]!=ch1: print('NO') sys.exit() if d[ch1]==-1: d[ch1]=l elif d[ch1]!=l: print('NO') sys.exit() l=ch1 x=[] def abc(c,d,e,i): e[i]=0 if c[i]==-1: return else: i=c[i] x.append(chr(i+97)) abc(c,d,e,i) for i in range(26): if e[i]==1 and d[i]==-1: x.append(chr(i+97)) abc(c,d,e,i) if sum(e)>0: print('NO') else: print(''.join(x)) # Made By Mostafa_Khaled ```
output
1
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` n = int(input()) A = [] for i in range (0,n): A = A + [input()] start = [100]*26 end = [100]*26 def num(x): return(ord(x)-ord("a")) def let(x): return(chr(x+ord("a"))) def ans(x): final = [] for i in range (0,n): B = list(A[i]) if len(B) == 1: if start[num(B[0])] == 100: start[num(B[0])] = -100 if end[num(B[0])] == 100: end[num(B[0])] = -100 else: for j in range (0,len(B)): if j==0: if start[num(B[j])] == 100 or start[num(B[j])] == -100: start[num(B[j])] = -100 if end[num(B[j])] == 100 or end[num(B[j])] == -100: end[num(B[j])] = num(B[j+1]) elif end[num(B[j])] == num(B[j+1]): g=0 else: return("NO") elif 0<j<len(B)-1: if start[num(B[j])] == 100 or start[num(B[j])] == -100: start[num(B[j])] = num(B[j-1]) elif start[num(B[j])] != num(B[j-1]): return("NO") if end[num(B[j])] == 100 or end[num(B[j])] == -100: end[num(B[j])] = num(B[j+1]) elif end[num(B[j])] != num(B[j+1]): return("NO") elif j == len(B)-1: if end[num(B[j])] == 100: end[num(B[j])] = -100 if start[num(B[j])] == 100 or start[num(B[j])] == -100: start[num(B[j])] = num(B[j-1]) elif start[num(B[j])] == num(B[j-1]): g=0 else: return("NO") if len(set(start))+max(0,start.count(100)-1)+max(0,start.count(-100)-1) != 26: return("NO") elif len(set(end))+max(0,end.count(100)-1)+max(0,end.count(-100)-1) != 26: return("NO") else: for i in range (0,26): if start[i] != -100: g=0 else: final = final + [let(i)] j = end[i] while j != -100: final = final + [let(j)] j = end[j] if len(final) != len(set(start))-min(1,start.count(100))+max(0,start.count(-100)-1): return("NO") else: return("".join(final)) print(ans(A)) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` n = int(input()) wrong_str = False strings = [] sets = [] for _ in range(n): new_string = input() new_string_set = set(new_string) if len(new_string) != len(new_string_set): wrong_str = True break strings.append(new_string) sets.append(new_string_set) if wrong_str: print("NO") exit(0) connections = [] for _ in range(n): connections.append((-1,-1)) changed = True while changed: changed = False for i in range(len(strings)): if strings[i] == None: continue for j in range(i + 1, len(strings)): if strings[j] == None: continue if len(set(strings[i]).intersection(set(strings[j]))) == 0: continue a = strings[i] b = strings[j] #print(a, b) if b in a: strings[j] = None changed = True elif a in b: strings[i] = b strings[j] = None changed = True else: is_ok = False start_index = a.find(b[0]) if start_index != -1 and a[start_index:] in b: strings[i] += strings[j][len(a) - start_index:] strings[j] = None is_ok = True changed = True if not is_ok: start_index = b.find(a[0]) if start_index != -1 and b[start_index:] in a: strings[i] = strings[j] + strings[i][len(b) - start_index:] strings[j] = None is_ok = True changed = True if not is_ok: print("NO") exit(0) if wrong_str: print("NO") exit(0) strings = [x for x in strings if x is not None] whole_str = "".join(strings) if len(whole_str) != len(set(whole_str)): print("NO") exit(0) print("".join(sorted(strings))) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` L = {} R = {} S = set() for _ in range(int(input())): s = input() if len(s) == 1: S.add(s) for s1, s2 in zip(s, s[1:]): if s2 != L.get(s1, s2) or s1 != R.get(s2, s1): exit(print('NO')) L[s1], R[s2] = s2, s1 L1, R1 = set(L), set(R) S = S -L1 - R1 for i in L1 - R1: while i[-1] in L: i += L.pop(i[-1]) S.add(i) if L: exit(print('NO')) print(''.join(sorted(S))) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` n = int(input()) last = [-1 for i in range(26)] left = [-1 for i in range(26)] right = [-1 for i in range(26)] for i in range(n): a = list(map(lambda x: ord(x) - ord('a'), input())) #print(a) for x in a: if last[x] == i: print('NO') exit(0) last[x] = i for j in range(len(a) - 1): x = a[j] y = a[j + 1] if left[y] != -1 and left[y] != x or\ right[x] != -1 and right[x] != y: print('NO') exit(0) left[y] = x right[x] = y sol = [] cnt = 0 for b in range(26): cnt += (last[b] > -1) if left[b] == -1 and last[b] > -1: sol.append(b) x = b while right[x] != -1: x = right[x] sol.append(x) if len(sol) == cnt: for x in sol: print(chr(x + ord('a')), end='') print() else: print('NO') ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` u, v = {}, {} for i in range(int(input())): t = input() for a, b in zip(t, t[1:]): if u.get(a, b) != b or v.get(b, a) != a: exit(print('NO')) u[a], v[b] = b, a d = [] for q in set(u).difference(v): while q[-1] in u: q += u.pop(q[-1]) d.append(q) if u: exit(print('NO')) print(''.join(sorted(d))) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` StringsNumber = int(input()) FinalStrings = [] Strings = [] for i in range(StringsNumber): Strings.append(input()) LetterGraph = {} # Генерим граф for i in range(len(Strings)): if len(Strings[i]) == 1: if Strings[i] not in LetterGraph: LetterGraph[Strings[i]] = "" #print("заапедил", i) continue for e in range(len(Strings[i]) - 1): if Strings[i][e] not in LetterGraph: Elements = [] for j in list(LetterGraph): if j != Strings[i][e + 1]: Elements.append(LetterGraph[j]) if Strings[i][e + 1] in Elements: print("NO") exit(0) LetterGraph[Strings[i][e]] = Strings[i][e + 1] continue if LetterGraph[Strings[i][e]] == Strings[i][e + 1] or LetterGraph[Strings[i][e]] == "": LetterGraph[Strings[i][e]] = Strings[i][e + 1] continue #print("Граф:", LetterGraph) print("NO") exit(0) #print("Я сгенерил граф, получилось:", LetterGraph) # Проверяем, что нету цикла if LetterGraph: Cycle = False for i in LetterGraph: if LetterGraph[i] in LetterGraph: if LetterGraph[LetterGraph[i]] == i: print("NO") exit(0) # Находим возможные первые символы if LetterGraph: IsIFirstSymbol = False FirstSymbols = [] for i in LetterGraph: IsIFirstSymbol = True for e in LetterGraph: if LetterGraph[e] == i: #print(i, "не подходит, потому что", e, "указывает на него.") IsIFirstSymbol = False if IsIFirstSymbol: FirstSymbols.append(i) if not FirstSymbols: print("NO") exit(0) #print("Варианты первого символа:", *FirstSymbols) # Создаем варианты финальной строки if LetterGraph: Letter = "" for i in FirstSymbols: FinalString = i Letter = i for e in range(len(LetterGraph)): if Letter in LetterGraph: if not (LetterGraph[Letter] == ""): FinalString += LetterGraph[Letter] #print(Letter, "есть в графе, так что добавляем", LetterGraph[Letter], ", на которое оно указывает.") Letter = LetterGraph[Letter] else: break else: break FinalStrings.append(FinalString) #print("Отдельные строки", *FinalStrings) FinalStrings.sort() RESULT = "" for i in FinalStrings: RESULT += i print(RESULT) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` n = int(input()) a = [] for i in range(n): a.append(input()) used = [0 for i in range(26)] ans = "" s = 'qwertyuioplkjhgfdsazxcvbnm' flag = True answer = [] while a: fl = False if not flag: break word = a[0] for q in range(len(word)): let = word[q] #print('let ',let) if word.count(let) > 1: flag = False break if fl: break for r in range(1, len(a)): k = a[r] if let in k: # print("here ",let, k) if (k.count(let) > 1): flag = False break if k in word or word in k: if k in word: a.pop(r) else: a.pop(0) fl = True break c = k.index(let) v1 = '' v2 = '' if (word[:q + 1:] == k[c::]): v1 = k + word[q + 1:] if (word[q:] == k[:c + 1]): v2 = word + k[c + 1:] if (v1 and v2): a.append(min(v1, v2)) else: if v1: a.append(v1) else: a.append(v2) a.pop(r) a.pop(0) fl = True break if not fl: #print(word) answer.append(word) a.pop(0) answer.sort() for i in answer: ans = ans + i if flag: print(ans) else: print('NO') ```
instruction
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62,004
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124,008
No
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. A substring of some string is called the most frequent, if the number of its occurrences is not less than number of occurrences of any other substring. You are given a set of strings. A string (not necessarily from this set) is called good if all elements of the set are the most frequent substrings of this string. Restore the non-empty good string with minimum length. If several such strings exist, restore lexicographically minimum string. If there are no good strings, print "NO" (without quotes). A substring of a string is a contiguous subsequence of letters in the string. For example, "ab", "c", "abc" are substrings of string "abc", while "ac" is not a substring of that string. The number of occurrences of a substring in a string is the number of starting positions in the string where the substring occurs. These occurrences could overlap. String a is lexicographically smaller than string b, if a is a prefix of b, or a has a smaller letter at the first position where a and b differ. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of strings in the set. Each of the next n lines contains a non-empty string consisting of lowercase English letters. It is guaranteed that the strings are distinct. The total length of the strings doesn't exceed 105. Output Print the non-empty good string with minimum length. If several good strings exist, print lexicographically minimum among them. Print "NO" (without quotes) if there are no good strings. Examples Input 4 mail ai lru cf Output cfmailru Input 3 kek preceq cheburek Output NO Note One can show that in the first sample only two good strings with minimum length exist: "cfmailru" and "mailrucf". The first string is lexicographically minimum. Submitted Solution: ``` def join_st(sf, pos, ans, start, end): for i in range(len(sf)): gt = pos.get(sf[i], None) if gt != None: gt = (gt, i) for k in range(i): if ans[gt[0] - k - 1] == '': ans[gt[0] - k - 1] = sf[i - k - 1] pos[sf[i - k - 1]] = gt[0] - k - 1 start -= 1 else: return 'NO' for k in range(i + 1, len(sf)): if ans[gt[0] + k - i] == '': ans[gt[0] + k - i] = sf[k] pos[sf[k]] = gt[0] + k - i elif ans[gt[0] + k - i] != sf[k]: return 'NO' return (ans, pos, start, end) if ans[start + 1] < sf[0]: for i in range(len(sf)): ans[end] = sf[i] pos[sf[i]] = end end += 1 else: for i in range(1, len(sf) + 1): ans[start] = sf[-i] pos[sf[-i]] = start start -= 1 return (ans, pos, start, end) def main(): n = int(input()) strings = ['' for i in range(n)] for i in range(n): strings[i] = input() pos = dict() ans = ['' for i in range(2 * 10 ** 5 + 2)] for i in range(len(strings[0])): ans[10 ** 5 + 1 + i] = strings[0][i] pos[strings[0][i]] = 10 ** 5 + 1 + i start = 10 ** 5 end = 10 ** 5 + len(strings[0]) + 1 for i in range(1, n): res = join_st(strings[i], pos, ans, start, end) if res == 'NO': print('NO') return else: ans, pos, start, end = res print(''.join(ans)) main() ```
instruction
0
62,005
0
124,010
No
output
1
62,005
0
124,011
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,125
0
124,250
"Correct Solution: ``` s = input() K = int(input()) n = len(s) t = s[::-1] if 2*K+1 >= n: print(n) exit() dp = [[[0 for i in range(K+1)] for j in range(n+1)] for k in range(n+1)] if n == 2 and K == 0: if s == t: print(2) exit() else: print(1) exit() ans = min(2*K+1,n) for center in range(1,n-1): flg = 0 sf = s[:center] sl = t[:n-center-1] if s[center] == s[center+1]: flg = 1 sfl = len(sf) sll = len(sl) for j in range(1,sll+1): dp[sfl][j][0] = max(dp[sfl-1][j][0],dp[sfl][j-1][0]) if sf[-1] != sl[j-1]: for k in range(1,K+1): dp[sfl][j][k] = max(dp[sfl-1][j-1][k-1]+1,dp[sfl-1][j][k],dp[sfl][j-1][k]) if sf[-1] == sl[j-1]: dp[sfl][j][0] = max(dp[sfl][j][0],dp[sfl-1][j-1][0]+1) for k in range(1,K+1): dp[sfl][j][k] = max(dp[sfl-1][j-1][k-1]+1,dp[sfl-1][j-1][k]+1,dp[sfl-1][j][k],dp[sfl][j-1][k]) if flg: ans= max(dp[sfl][sll][K]*2+1,dp[sfl][sll-1][K]*2+2,ans) elif K > 0: ans= max(dp[sfl][sll][K]*2+1,dp[sfl][sll-1][K-1]*2+2,ans) else: ans= max(dp[sfl][sll][K]*2+1,ans) print(ans) ```
output
1
62,125
0
124,251
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,126
0
124,252
"Correct Solution: ``` def get_ind(l, r): mod = 3 return OFFSET * (l % mod) + r s = input() n = len(s) k = int(input()) dp = [[0] * ((n + 1) * 3) for i in range(k + 1)] OFFSET = n + 1 # 長さ1のときの初期化 for i in range(n): dp[0][get_ind(i, i + 1)] = 1 # 長さ2~nのときのDP for length in range(2, n + 1): for l in range(n + 1): for ki in range(k + 1): r = l + length if r > n: break if s[l] == s[r - 1]: dp[ki][get_ind(l, r)] = max(2 + dp[ki][get_ind(l + 1, r - 1)], dp[ki][get_ind(l, r)]) else: dp[ki][get_ind(l, r)] = max(dp[ki][get_ind(l + 1, r)], dp[ki][get_ind(l, r - 1)], dp[ki][get_ind(l, r)]) if ki - 1 >= 0: dp[ki][get_ind(l, r)] = max(dp[ki - 1][get_ind(l + 1, r - 1)] + 2, dp[ki][get_ind(l, r)]) ans = 0 for i in range(k + 1): for j in range(3 * (n + 1)): ans = max(ans, dp[i][j]) print(ans) ```
output
1
62,126
0
124,253
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,127
0
124,254
"Correct Solution: ``` """ https://atcoder.jp/contests/agc021/tasks/agc021_d ある部分でcutしたとする。 前半と後半のLCSを求めたとすると、交差した後のLCSの長さも同じ →左からindex iまでと右からindex jまでのLCSを求めればいい (i < j) あとは、普通のLCSと同様のdpでいける dp[i][j][k] = 左からi番目の文字までと、右からindex jの文字までのk回替えた際のLCS長さ あとは2倍すれば大体行ける? i+1 == jでは、2倍すればおk i+1 < j では、真ん中の文字を使えるので、2倍して1足す """ import sys S = input() S = " "+S K = int(input()) N = len(S)-1 if N == 1: print (1) sys.exit() elif N == 2: if S[1] == S[2] or K > 0: print (2) else: print (1) sys.exit() dp = [[[0] * (K+1) for i in range(N+2)]] ans = 0 for i in range(1,N+1): dp.append( [[0] * (K+1) for i in range(N+2)] ) for j in range(N,i,-1): for k in range(K+1): #同じ場合、どっちも進める if S[i] == S[j]: dp[i][j][k] = max( dp[i][j][k] , dp[i-1][j+1][k] + 1) else: dp[i][j][k] = max( dp[i][j][k] , dp[i-1][j][k] , dp[i][j+1][k] ) if k != 0: dp[i][j][k] = max(dp[i][j][k] , dp[i-1][j+1][k-1] + 1) if i+1 == j: ans = max(ans , dp[i][j][k] * 2) else: ans = max(ans , dp[i][j][k] * 2 + 1) dp[i-1] = [] print (ans) ```
output
1
62,127
0
124,255
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,128
0
124,256
"Correct Solution: ``` def examA(): N = I() ans = 0 print(ans) return # 参考 https://atcoder.jp/contests/agc021/submissions/8392122 def examB(): def norm2(vec): return math.sqrt(vec[0] ** 2 + vec[1] ** 2) # any 2 points must have different position. def ConvexHull(point_list): pos2idx = {point_list[i]: i for i in range(len(point_list))} y_val = defaultdict(list) x_list = sorted(list(set([p[0] for p in point_list]))) for x, y in point_list: y_val[x].append(y) upper = [(x_list[0], max(y_val[x_list[0]]))] lower = [(x_list[0], min(y_val[x_list[0]]))] prev = float('inf') for xi in x_list[1:]: x0, y0 = upper[-1] x1, y1 = xi, max(y_val[xi]) if (y1 - y0) / (x1 - x0) < prev: upper.append((x1, y1)) prev = (y1 - y0) / (x1 - x0) else: while True: x0, y0 = upper[-1] if len(upper) == 1: upper.append((x1, y1)) break x00, y00 = upper[-2] if (y1 - y0) / (x1 - x0) > (y1 - y00) / (x1 - x00): upper.pop() else: prev = (y1 - y0) / (x1 - x0) upper.append((x1, y1)) break prev = -float('inf') for xi in x_list[1:]: x0, y0 = lower[-1] x1, y1 = xi, min(y_val[xi]) if (y1 - y0) / (x1 - x0) > prev: lower.append((x1, y1)) prev = (y1 - y0) / (x1 - x0) else: while True: x0, y0 = lower[-1] if len(lower) == 1: lower.append((x1, y1)) break x00, y00 = lower[-2] if (y1 - y0) / (x1 - x0) < (y1 - y00) / (x1 - x00): lower.pop() else: prev = (y1 - y0) / (x1 - x0) lower.append((x1, y1)) break # return upper, lower # return [pos2idx[xy] for xy in upper], [pos2idx[xy] for xy in lower] upper_idx, lower_idx = [pos2idx[xy] for xy in upper], [pos2idx[xy] for xy in lower] if upper_idx[-1] == lower_idx[-1]: upper_idx.pop() CH_idx = upper_idx CH_idx.extend(reversed(lower_idx)) if CH_idx[0] == CH_idx[-1] and len(CH_idx) > 1: CH_idx.pop() return CH_idx N = I() P = [[]for _ in range(N)] D = defaultdict(int) for i in range(N): x,y = LI() P[i] = (x,y) D[(x,y)] = i C = ConvexHull(P) ans = [0]*N if len(C)==2: for c in C: ans[c] = 0.5 for v in ans: print(v) return #print(C) for i,c in enumerate(C): s, t, u = C[i - 1], C[i], C[(i + 1) % len(C)] x0, y0 = P[s] x1, y1 = P[t] x2, y2 = P[u] vec0 = (y0 - y1, x1 - x0) vec1 = (y1 - y2, x2 - x1) ans[t] = math.acos((vec0[0] * vec1[0] + vec0[1] * vec1[1]) / (norm2(vec0) * norm2(vec1))) / (2 * math.pi) for v in ans: print(v) return def examC(): ans = 0 print(ans) return def examD(): S = SI() N = len(S) K = I() if K>150: K = 150 dp = [[[0]*(K+1) for _ in range(N)] for i in range(N)] for i in range(N): for j in range(K+1): dp[i][i][j] = 1 for i in range(2,N+1): for k in range(K+1): for l,r in enumerate(range(i-1,N)): if S[l]==S[r]: dp[l][r][k] = dp[l+1][r-1][k] + 2 else: if k>0: dp[l][r][k] = max(dp[l+1][r][k],dp[l][r-1][k],dp[l+1][r-1][k-1]+2) else: dp[l][r][k] = max(dp[l + 1][r][k], dp[l][r - 1][k]) ans = max(dp[0][-1]) #print(dp) print(ans) return def examE(): ans = 0 print(ans) return def examF(): ans = 0 print(ans) return from decimal import Decimal as dec import sys,bisect,itertools,heapq,math,random from copy import deepcopy from heapq import heappop,heappush,heapify from collections import Counter,defaultdict,deque read = sys.stdin.buffer.read readline = sys.stdin.buffer.readline readlines = sys.stdin.buffer.readlines def I(): return int(input()) def LI(): return list(map(int,sys.stdin.readline().split())) def DI(): return dec(input()) def LDI(): return list(map(dec,sys.stdin.readline().split())) def LSI(): return list(map(str,sys.stdin.readline().split())) def LS(): return sys.stdin.readline().split() def SI(): return sys.stdin.readline().strip() global mod,mod2,inf,alphabet,_ep mod = 10**9 + 7 mod2 = 998244353 inf = 10**18 _ep = 10**(-12) alphabet = [chr(ord('a') + i) for i in range(26)] sys.setrecursionlimit(10**7) if __name__ == '__main__': examD() """ 142 12 9 1445 0 1 asd dfg hj o o aidn """ ```
output
1
62,128
0
124,257
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,129
0
124,258
"Correct Solution: ``` import sys readline = sys.stdin.buffer.readline ns = lambda: readline().rstrip() ni = lambda: int(readline().rstrip()) nm = lambda: map(int, readline().split()) nl = lambda: list(map(int, readline().split())) def solve(): s = list(ns()) ls = len(s) lk = ni() dp = [[[0]*ls for _ in range(ls)] for i in range(2)] ans = 0 for i in range(ls): dp[0][i][i] = 1 for k in range(lk+1): v = k & 1 for dis in range(1, ls): for i in range(ls - dis): j = i + dis dp[v][i][j] = 0 if s[i] == s[j]: dp[v][i][j] = dp[v][i+1][j-1] + 2 elif k: dp[v][i][j] = dp[v^1][i+1][j-1] + 2 dp[v][i][j] = max(dp[v][i][j], dp[v][i+1][j], dp[v][i][j-1]) ans = max(ans, dp[v][0][-1]) print(ans) return solve() ```
output
1
62,129
0
124,259
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,130
0
124,260
"Correct Solution: ``` def main(): s = input() n = len(s) k = int(input()) # dp[使った回数][左端からの距離][左端] dp = [[[1]*(n-i) for i in range(n)] for _ in range(k+1)] for i in range(n-1): if s[i] == s[i+1]: dp[0][1][i] = 2 if k > 0: for cnt in range(1, k+1): for i in range(n-1): dp[cnt][1][i] = 2 for cnt in range(k): for d in range(2, n): for left in range(n-d): right = left+d plus = (s[left] == s[right])*2 dp[cnt][d][left] = max( dp[cnt][d][left], dp[cnt][d-1][left], dp[cnt][d-1][left+1], dp[cnt][d-2][left+1]+plus) dp[cnt+1][d][left] = max( dp[cnt+1][d][left], dp[cnt][d][left], dp[cnt][d-2][left+1]+2) for d in range(2, n): for left in range(n-d): right = left+d plus = (s[left] == s[right])*2 dp[k][d][left] = max( dp[k][d][left], dp[k][d-1][left], dp[k][d-1][left+1], dp[k][d-2][left+1]+plus) print(dp[-1][-1][0]) main() ```
output
1
62,130
0
124,261
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,131
0
124,262
"Correct Solution: ``` def main(): s = input() n = len(s) k = int(input()) # dp[使った回数][左端からの距離][左端] dp = [[[1]*(n-i) for i in range(n)] for _ in range(k+1)] if n == 1: print(1) return dp2 = dp[0][1] for i in range(n-1): if s[i] == s[i+1]: dp2[i] = 2 if k > 0: for cnt in range(1, k+1): dp2 = dp[cnt][1] for i in range(n-1): dp2[i] = 2 for cnt in range(k): dp2 = dp[cnt] for d in range(2, n): dp3 = dp2[d] for left in range(n-d): right = left+d plus = (s[left] == s[right])*2 dp3[left] = max( dp3[left], dp2[d-1][left], dp2[d-1][left+1], dp2[d-2][left+1]+plus) dp[cnt+1][d][left] = max( dp[cnt+1][d][left], dp3[left], dp2[d-2][left+1]+2) dp2 = dp[k] for d in range(2, n): dp3 = dp2[d] for left in range(n-d): right = left+d plus = (s[left] == s[right])*2 dp3[left] = max( dp3[left], dp2[d-1][left], dp2[d-1][left+1], dp2[d-2][left+1]+plus) print(dp[-1][-1][0]) main() ```
output
1
62,131
0
124,263
Provide a correct Python 3 solution for this coding contest problem. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15
instruction
0
62,132
0
124,264
"Correct Solution: ``` def solve(s, k): n = len(s) pdp = [[0] * (k + 1) for _ in range(n + 1)] for l in range(n - 1, -1, -1): dp = [[0] * (k + 1) for _ in range(n + 1)] for r in range(l, n): dpr, dpr1 = dp[r], pdp[r - 1] inc = 1 if l == r else 2 is_same = s[l] == s[r] for p in range(k + 1): if is_same: dpr[p] = dpr1[p] + inc else: if p: dpr[p] = max(pdp[r][p], dp[r - 1][p], dpr1[p - 1] + inc) else: dpr[p] = max(pdp[r][p], dp[r - 1][p]) pdp = dp return pdp[-2][k] print(solve(input(), int(input()))) ```
output
1
62,132
0
124,265
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` import sys readline = sys.stdin.readline S = list(map(ord, readline().strip())) N = len(S) S = [None] + S + [None] K = int(readline()) if N == 1: ans = 1 elif N == 2: ans = 1 if S[1] == S[2]: ans = 2 if K: ans = 2 else: dp1 = [[0]*(K+1) for _ in range(N+2)] dp2 = [[0]*(K+1) for _ in range(N+2)] for i in range(1, N+1): dp1[i][0] = 1 for i in range(1, N): dp2[i][0] = 1 if S[i] == S[i+1]: dp2[i][0] = 2 elif K: dp2[i][1] = 2 for s in range(3, N+1): dp3 = [[0]*(K+1) for _ in range(N+2)] for i in range(1, N-s+2): j = i+s-1 if S[i] == S[j]: for k in range(K+1): dp3[i][k] = max(dp2[i+1][k], dp2[i][k], 2+dp1[i+1][k]) else: dp3[i][0] = max(dp2[i+1][0], dp2[i][0], dp2[i+1][0]) for k in range(1, K+1): dp3[i][k] = max(dp2[i+1][k], dp2[i][k], dp1[i+1][k], 2+dp1[i+1][k-1]) dp1 = [k[:] for k in dp2] dp2 = [k[:] for k in dp3] ans = max(dp3[1][k] for k in range(K+1)) print(ans) ''' MLEした dp = [[[0]*(K+1) for _ in range(N+2)] for _ in range(N+2)] for i in range(1, N+1): dp[i][i][0] = 1 for i in range(1, N): dp[i][i+1][0] = 1 if S[i] == S[i+1]: dp[i][i+1][0] = 2 elif K: dp[i][i+1][1] = 2 for s in range(3, N+1): for i in range(1, N-s+2): j = i+s-1 if S[i] == S[j]: for k in range(K+1): dp[i][j][k] = max(dp[i+1][j][k], dp[i][j-1][k], 2+dp[i+1][j-1][k]) else: dp[i][j][0] = max(dp[i+1][j][0], dp[i][j-1][0], dp[i+1][j-1][0]) for k in range(1, K+1): dp[i][j][k] = max(dp[i+1][j][k], dp[i][j-1][k], dp[i+1][j-1][k], 2+dp[i+1][j-1][k-1], dp[i+1][j-1][k]) print(max(dp[1][N][k] for k in range(K+1))) ''' ```
instruction
0
62,133
0
124,266
Yes
output
1
62,133
0
124,267
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` import sys readline = sys.stdin.readline S = list(map(ord, readline().strip())) N = len(S) S = [None] + S + [None] K = int(readline()) if N == 1: ans = 1 elif N == 2: ans = 1 if S[1] == S[2]: ans = 2 if K: ans = 2 else: dp1 = [[0]*(K+1) for _ in range(N+2)] dp2 = [[0]*(K+1) for _ in range(N+2)] for i in range(1, N+1): dp1[i][0] = 1 for i in range(1, N): dp2[i][0] = 1 if S[i] == S[i+1]: dp2[i][0] = 2 elif K: dp2[i][1] = 2 for s in range(3, N+1): dp3 = [[0]*(K+1) for _ in range(N+2)] for i in range(1, N-s+2): j = i+s-1 if S[i] == S[j]: for k in range(K+1): dp3[i][k] = max(dp2[i+1][k], dp2[i][k], 2+dp1[i+1][k]) else: dp3[i][0] = max(dp2[i+1][0], dp2[i][0], dp2[i+1][0]) for k in range(1, K+1): dp3[i][k] = max(dp2[i+1][k], dp2[i][k], dp1[i+1][k], 2+dp1[i+1][k-1]) ''' dp1 = [k[:] for k in dp2] dp2 = [k[:] for k in dp3] ''' dp1 = dp2[:] dp2 = dp3[:] ans = max(dp3[1][k] for k in range(K+1)) print(ans) ''' MLEした dp = [[[0]*(K+1) for _ in range(N+2)] for _ in range(N+2)] for i in range(1, N+1): dp[i][i][0] = 1 for i in range(1, N): dp[i][i+1][0] = 1 if S[i] == S[i+1]: dp[i][i+1][0] = 2 elif K: dp[i][i+1][1] = 2 for s in range(3, N+1): for i in range(1, N-s+2): j = i+s-1 if S[i] == S[j]: for k in range(K+1): dp[i][j][k] = max(dp[i+1][j][k], dp[i][j-1][k], 2+dp[i+1][j-1][k]) else: dp[i][j][0] = max(dp[i+1][j][0], dp[i][j-1][0], dp[i+1][j-1][0]) for k in range(1, K+1): dp[i][j][k] = max(dp[i+1][j][k], dp[i][j-1][k], dp[i+1][j-1][k], 2+dp[i+1][j-1][k-1], dp[i+1][j-1][k]) print(max(dp[1][N][k] for k in range(K+1))) ''' ```
instruction
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62,134
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124,268
Yes
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` import sys input = lambda : sys.stdin.readline().rstrip() sys.setrecursionlimit(max(1000, 10**9)) write = lambda x: sys.stdout.write(x+"\n") s = input() K = int(input()) n = len(s) dp = [[[0]*(K+1) for _ in range(n+2-i)] for i in range(n+1)] for i in range(n): for j in range(K+1): dp[i][1][j] = 1 for l in range(2, n+1): for i in range(n-l+1): for k in range(K+1): # print(l, i, i+l, j) if s[i]==s[i+l-1]: dp[i][l][k] = dp[i+1][l-2][k] + 2 else: dp[i][l][k] = max(dp[i+1][l-1][k], dp[i][l-1][k]) if k>=1: dp[i][l][k] = max(dp[i][l][k], dp[i+1][l-2][k-1]+2) ans = max(dp[0][i][j] for i in range(n+2) for j in range(K+1)) print(ans) ```
instruction
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124,270
Yes
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62,135
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` S = input() K = int(input()) N = len(S) # MLE対策 if K * 2 >= N-1: print(N) exit() dp = [[[0 for _ in range(K+1)] for _ in range(N)] for _ in range(N)] for i in range(N): for k in range(K+1): dp[i][i][k] = 1 for _j in range(1, N): for i in range(N): j = i + _j if j < N: for k in range(K+1): dp[i][j][k] = max(dp[i][j][k], dp[i+1][j][k], dp[i][j-1][k]) if _j == 1: if S[i] == S[j]: dp[i][j][k] = 2 else: if k+1 <= K: dp[i][j][k+1] = 2 else: if S[i] == S[j]: dp[i][j][k] = max(dp[i][j][k], dp[i+1][j-1][k] + 2) else: if k+1 <= K: dp[i][j][k+1] = max(dp[i][j][k], dp[i+1][j-1][k] + 2) print(max(dp[0][N-1])) ```
instruction
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62,136
0
124,272
Yes
output
1
62,136
0
124,273
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` def examA(): N = I() ans = 0 print(ans) return # 参考 https://atcoder.jp/contests/agc021/submissions/8392122 def examB(): def norm2(vec): return math.sqrt(vec[0] ** 2 + vec[1] ** 2) # any 2 points must have different position. def ConvexHull(point_list): pos2idx = {point_list[i]: i for i in range(len(point_list))} y_val = defaultdict(list) x_list = sorted(list(set([p[0] for p in point_list]))) for x, y in point_list: y_val[x].append(y) upper = [(x_list[0], max(y_val[x_list[0]]))] lower = [(x_list[0], min(y_val[x_list[0]]))] prev = float('inf') for xi in x_list[1:]: x0, y0 = upper[-1] x1, y1 = xi, max(y_val[xi]) if (y1 - y0) / (x1 - x0) < prev: upper.append((x1, y1)) prev = (y1 - y0) / (x1 - x0) else: while True: x0, y0 = upper[-1] if len(upper) == 1: upper.append((x1, y1)) break x00, y00 = upper[-2] if (y1 - y0) / (x1 - x0) > (y1 - y00) / (x1 - x00): upper.pop() else: prev = (y1 - y0) / (x1 - x0) upper.append((x1, y1)) break prev = -float('inf') for xi in x_list[1:]: x0, y0 = lower[-1] x1, y1 = xi, min(y_val[xi]) if (y1 - y0) / (x1 - x0) > prev: lower.append((x1, y1)) prev = (y1 - y0) / (x1 - x0) else: while True: x0, y0 = lower[-1] if len(lower) == 1: lower.append((x1, y1)) break x00, y00 = lower[-2] if (y1 - y0) / (x1 - x0) < (y1 - y00) / (x1 - x00): lower.pop() else: prev = (y1 - y0) / (x1 - x0) lower.append((x1, y1)) break # return upper, lower # return [pos2idx[xy] for xy in upper], [pos2idx[xy] for xy in lower] upper_idx, lower_idx = [pos2idx[xy] for xy in upper], [pos2idx[xy] for xy in lower] if upper_idx[-1] == lower_idx[-1]: upper_idx.pop() CH_idx = upper_idx CH_idx.extend(reversed(lower_idx)) if CH_idx[0] == CH_idx[-1] and len(CH_idx) > 1: CH_idx.pop() return CH_idx N = I() P = [[]for _ in range(N)] D = defaultdict(int) for i in range(N): x,y = LI() P[i] = (x,y) D[(x,y)] = i C = ConvexHull(P) ans = [0]*N if len(C)==2: for c in C: ans[c] = 0.5 for v in ans: print(v) return #print(C) for i,c in enumerate(C): s, t, u = C[i - 1], C[i], C[(i + 1) % len(C)] x0, y0 = P[s] x1, y1 = P[t] x2, y2 = P[u] vec0 = (y0 - y1, x1 - x0) vec1 = (y1 - y2, x2 - x1) ans[t] = math.acos((vec0[0] * vec1[0] + vec0[1] * vec1[1]) / (norm2(vec0) * norm2(vec1))) / (2 * math.pi) for v in ans: print(v) return def examC(): ans = 0 print(ans) return def examD(): S = SI() N = len(S) K = I() dp = defaultdict(lambda:[0 for _ in range(K+1)]) for i in range(N): for j in range(K+1): dp[(i,i)][j] = 1 for i in range(2,N+1): for k in range(K+1): for l,r in enumerate(range(i-1,N)): if S[l]==S[r]: dp[(l,r)][k] = dp[(l+1,r-1)][k] + 2 else: if k>0: dp[(l,r)][k] = max(dp[(l+1,r)][k],dp[(l,r-1)][k],dp[(l+1,r-1)][k-1]+2) else: dp[(l,r)][k] = max(dp[(l + 1,r)][k], dp[(l,r - 1)][k]) ans = max(dp[(0,N-1)]) #print(dp) print(ans) return def examE(): ans = 0 print(ans) return def examF(): ans = 0 print(ans) return from decimal import Decimal as dec import sys,bisect,itertools,heapq,math,random from copy import deepcopy from heapq import heappop,heappush,heapify from collections import Counter,defaultdict,deque read = sys.stdin.buffer.read readline = sys.stdin.buffer.readline readlines = sys.stdin.buffer.readlines def I(): return int(input()) def LI(): return list(map(int,sys.stdin.readline().split())) def DI(): return dec(input()) def LDI(): return list(map(dec,sys.stdin.readline().split())) def LSI(): return list(map(str,sys.stdin.readline().split())) def LS(): return sys.stdin.readline().split() def SI(): return sys.stdin.readline().strip() global mod,mod2,inf,alphabet,_ep mod = 10**9 + 7 mod2 = 998244353 inf = 10**18 _ep = 10**(-12) alphabet = [chr(ord('a') + i) for i in range(26)] sys.setrecursionlimit(10**7) if __name__ == '__main__': examD() """ 142 12 9 1445 0 1 asd dfg hj o o aidn """ ```
instruction
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62,137
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124,274
No
output
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62,137
0
124,275
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` import sys input = sys.stdin.buffer.readline S = list(input().rstrip()) K = int(input()) L = len(S) def main(): dp = [[[0]*(K+1) for _ in range(L+1)] for _ in range(L+1)] ans = 0 for ind in reversed(range(L)): # [0, ind), [ind, L-1] s = S[ind] for i in range(ind): for k in reversed(range(K+1)): if S[i] == s: dp[i+1][L-ind][k] = dp[i][L-ind-1][k] + 1 else: dp[i+1][L-ind][k] = max(dp[i][L-ind][k], dp[i+1][L-ind-1][k]) if k < K: dp[i+1][L-ind][k+1] = max(dp[i+1][L-ind][k+1], dp[i+1][L-ind][k]+1) for k in range(K+1): ans = max(ans, 2*dp[ind][L-ind][k]) ans = max(ans, 2*dp[ind][L-ind-1][k] + 1) print(ans) if __name__ == "__main__": main() ```
instruction
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124,276
No
output
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62,138
0
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` def main(): s = input() n = len(s) k = int(input()) # dp[左端][左端からの右端の距離][使った回数] dp = [[[1]*(k+1) for _ in [0]*(n-i)] for i in range(n)] for i in range(n-1): if s[i] == s[i+1]: dp[i][1][0] = 2 for cnt in range(k): for d in range(2, n): for left in range(n-d): right = left+d plus = (s[left] == s[right])*2 dp[left][d][cnt] = max( dp[left][d][cnt], dp[left][d-1][cnt], dp[left+1][d-1][cnt], dp[left+1][d-2][cnt]+plus) dp[left][d][cnt+1] = max( max(dp[left][d][cnt:cnt+2]), dp[left+1][d-2][cnt]+2) for d in range(2, n): for left in range(n-d): right = left+d plus = (s[left] == s[right])*2 dp[left][d][k] = max( dp[left][d][k], dp[left][d-1][k], dp[left+1][d-1][k], dp[left+1][d-2][k]+plus) print(dp[0][-1][-1]) main() ```
instruction
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62,139
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124,278
No
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1
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Takahashi has decided to give a string to his mother. The value of a string T is the length of the longest common subsequence of T and T', where T' is the string obtained by reversing T. That is, the value is the longest length of the following two strings that are equal: a subsequence of T (possibly non-contiguous), and a subsequence of T' (possibly non-contiguous). Takahashi has a string S. He wants to give her mother a string of the highest possible value, so he would like to change at most K characters in S to any other characters in order to obtain a string of the highest possible value. Find the highest possible value achievable. Constraints * 1 \leq |S| \leq 300 * 0 \leq K \leq |S| * S consists of lowercase English letters. * K is an integer. Input Input is given from Standard Input in the following format: S K Output Print the highest possible value achievable. Examples Input abcabcabc 1 Output 7 Input atcodergrandcontest 3 Output 15 Submitted Solution: ``` def lcs(str1, str2): '''文字列str1, str2の最長共通部分列(Lowest Common Subsequence, LCS)を求める 計算量O(len(str1)*len(str2)) ''' dp = [[0]*(len(str2) + 1) for _ in range(len(str1) + 1)] for i in range(len(str1)): for j in range(len(str2)): if str1[i] == str2[j]: dp[i+1][j+1] = dp[i][j] + 1 else: dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j]) return dp[len(str1)][len(str2)] s = input() n = len(s) k = int(input()) ans = 0 for i in range(n): t = s[0:i] rev_t = s[i+1:][::-1] min_len = min(len(t), len(rev_t)) ans = max(min(lcs(t, rev_t) + k, min_len) * 2 + 1, ans) for i in range(n + 1): t = s[0:i] rev_t = s[i:][::-1] min_len = min(len(t), len(rev_t)) ans = max(min(lcs(t, rev_t) + k, min_len) * 2, ans) print(ans) ```
instruction
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62,140
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124,280
No
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Provide a correct Python 3 solution for this coding contest problem. Almost periodic string Given the string S. Answer Q queries for this string S. In the i-th query, determine if S [l_i, \ r_i] can be a string of period t_i when you can change from S [l_i, \ r_i] to one character. S [l, \ r] represents the substring of the string S from the lth to the rth. If the character string W is a character string with period t, then for i \ = \ 1, \ 2, \ ..., \ | W | − t, W_ {i} = W_ {i + t}. I will do it. Constraints * 1 ≤ | S | ≤ 10 ^ 5 * 1 ≤ Q ≤ 10 ^ 5 * 1 ≤ l_i ≤ r_i ≤ | S | * 1 ≤ t_i ≤ r_i − l_i + 1 * S consists of only lowercase letters Input Format Input is given from standard input in the following format. S Q l_1 r_1 t_1 ... l_Q r_Q t_Q Output Format Output over Q lines. On line i, print the answer to the i-th query with `Yes` or` No`. Sample Input 1 abcabcaxcabc Four 1 9 3 8 12 3 1 4 2 2 3 2 Sample Output 1 Yes Yes No Yes Sample Input 2 isuruu Four 3 6 1 3 6 2 3 6 3 2 4 1 Sample Output 2 Yes Yes Yes No Example Input abcabcaxcabc 4 1 9 3 8 12 3 1 4 2 2 3 2 Output Yes Yes No Yes
instruction
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"Correct Solution: ``` import sys readline = sys.stdin.readline write = sys.stdout.write def solve(): base = 37; MOD = 10**9 + 9 S = readline().strip() L = len(S) H = [0]*(L+1) pw = [1]*(L+1) ca = ord('a') v = 0 for i in range(L): H[i+1] = v = (v * base + (ord(S[i]) - ca)) % MOD v = 1 for i in range(1, L+1): pw[i] = v = v * base % MOD Q = int(readline()) for i in range(Q): l, r, t = map(int, readline().split()); l -= 1 m = r-l if ((H[r]-H[r-t]) - (H[l+t]-H[l]) * pw[m-t]) % MOD == 0: write("Yes\n") continue left = 0; right = m-t+1 base = H[l] - H[l+t] while left+1 < right: mid = (left + right) >> 1 if ((H[l+mid]-H[l+t+mid]) - base * pw[mid]) % MOD == 0: left = mid else: right = mid l1 = left left = 0; right = m-t-l1+1 base = (H[r-t]-H[r]) % MOD while left+1 < right: mid = (left + right) >> 1 if (H[r-t-mid]-H[r-mid]) * pw[mid] % MOD == base: left = mid else: right = mid l2 = left if l1+l2+1 == m-t: if l1 <= t or l2 <= t: write("Yes\n") else: write("No\n") else: if ((H[l+m-t-l2-1]-H[l+m-l2-1]) - (H[l+l1+1]-H[l+t+l1+1]) * pw[m-t-l2-l1-2]) % MOD != 0: write("No\n") else: p1 = l1; p2 = m-t-l2-1 if p2 - p1 == t and S[l+p2-t] == S[l+p2+t]: write("Yes\n") else: write("No\n") solve() ```
output
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Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
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124,618
Tags: combinatorics, dp, implementation Correct Solution: ``` s = input() A = [] a = 0 b = 0 for i in range(len(s)): if s[i] == 'a': a += 1 b = 0 if s[i] == 'b': b += 1 if a > 0: A.append(a); a = 0 if a > 0: A.append(a) if len(A) > 0: dp = [0] * (len(A) + 1) dp[0] = A[0] for i in range(1, len(A)): dp[i] = dp[i - 1] + A[i] * (1 + dp[i - 1]) print(dp[len(A) - 1] % 1000000007) else: print(0) ```
output
1
62,309
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124,619
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,310
0
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Tags: combinatorics, dp, implementation Correct Solution: ``` r = t = 0 s = input() p = list(s) for k in s: if k == 'b': t = r if k == 'a': r = (r + t + 1) % (10**9 + 7) print(r) ```
output
1
62,310
0
124,621
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,311
0
124,622
Tags: combinatorics, dp, implementation Correct Solution: ``` s = input() mod = 10**9 + 7 L = [] c = 0 f = 0 for i in s: if i == 'a': f = 0 c += 1 elif i == 'b' and f == 0: L.append(c) c = 0 f = 1 if c > 0 and f == 0: L.append(c) res = 1 for i in range(len(L)): res *= (L[i]+1)%mod print((res-1)%mod) ```
output
1
62,311
0
124,623
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,312
0
124,624
Tags: combinatorics, dp, implementation Correct Solution: ``` mod = int(1e9) + 7 s = input() n = len(s) ans = 1 kol = 0 tmp = 0 for c in s: if c == 'b': ans *= (kol + 1) ans = ans % mod kol = 0 if c == 'a': kol += 1 tmp += 1 print((ans * (kol + 1) - 1) % mod) ```
output
1
62,312
0
124,625
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,313
0
124,626
Tags: combinatorics, dp, implementation Correct Solution: ``` import re s = input() s = re.sub(r'[^a-b]', '', s) s = re.sub(r'b+', 'b', s) next_b = [len(s)-1 for _ in range(len(s))] last_b_index = -1 i = len(s) - 1 while i>=0: if last_b_index !=-1: next_b[i] = last_b_index if s[i] == 'b': last_b_index = i i -= 1 dp = [-1 for _ in range(len(s)+1)] dp[len(s)] = 0 i = len(s) - 1 while i>=0: dp[i] = dp[i + 1] if s[i] == 'a': dp[i] += 1 + (dp[next_b[i]+1]) dp[i] %= 1000000007 i -= 1 print(dp[0]) ```
output
1
62,313
0
124,627
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,314
0
124,628
Tags: combinatorics, dp, implementation Correct Solution: ``` import sys if __name__ == "__main__": # single variables s = [str(val) for val in input().split()][0] singles = 0 for i in s: if(i == 'a'): singles +=1 count = 0 groups = [] for i in s: if(i == 'a'): count += 1 if(i == 'b' and count != 0): groups.append(count) count = 0 if(count != 0): groups.append(count) modval = int(1e9+7) tots = 1 for i in groups: tots = ((tots % modval) * ((i+1) % modval)) % modval print(tots-1) ```
output
1
62,314
0
124,629
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,315
0
124,630
Tags: combinatorics, dp, implementation Correct Solution: ``` line = list(input()) + ['b'] a = [] count = 0 for i in line: if i == 'b' and count > 0: a.append(count) count = 0 if i == 'a': count += 1 ans = 1 for i in a: ans *= i + 1 ans %= 1000000007 print(ans - 1) ```
output
1
62,315
0
124,631
Provide tags and a correct Python 3 solution for this coding contest problem. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4].
instruction
0
62,316
0
124,632
Tags: combinatorics, dp, implementation Correct Solution: ``` st, count, ans = input(), 0, 1 for char in st: if (char == 'a'): count+=1 elif(char == 'b' and count > 0): ans*=(count+1) count = 0 ans = (ans*(count+1)-1) if count > 0 else ans-1 print(ans%(10**9+7)) ```
output
1
62,316
0
124,633
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` s = input() m = 10**9+7 a = [] j = 0 for i in range(len(s)): if s[i] == 'b': a.append(j) j = 0 elif s[i] == 'a': j += 1 if j != 0: a.append(j) if len(a) == 0: print(0) exit() ans = a[0] for i in range(1, len(a)): ans = (ans+ans*a[i]+a[i])%m print(ans) ```
instruction
0
62,317
0
124,634
Yes
output
1
62,317
0
124,635
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` old_palavra = input() a_palavra = [] for letra in old_palavra: if letra == "a": a_palavra.append(letra) if letra == "b" and len(a_palavra) > 0 and a_palavra[-1] == "a": a_palavra.append(letra) matrix_palavra = [[]] arrayinterno = 0 for i in a_palavra: if i == "a": matrix_palavra[arrayinterno].append(i) else: matrix_palavra.append([]) arrayinterno += 1 tamanhos_de_arrays = [] for i in matrix_palavra: tamanhos_de_arrays.append(len(i) +1) resultado = tamanhos_de_arrays[0] for i in range(1, len(tamanhos_de_arrays)): resultado *= tamanhos_de_arrays[i] print((resultado -1) % 1000000007) ```
instruction
0
62,318
0
124,636
Yes
output
1
62,318
0
124,637
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` import sys import os from io import BytesIO, IOBase ######################### # imgur.com/Pkt7iIf.png # ######################### # returns the list of prime numbers less than or equal to n: '''def sieve(n): if n < 2: return list() prime = [True for _ in range(n + 1)] p = 3 while p * p <= n: if prime[p]: for i in range(p * 2, n + 1, p): prime[i] = False p += 2 r = [2] for p in range(3, n + 1, 2): if prime[p]: r.append(p) return r''' # returns all the divisors of a number n(takes an additional parameter start): '''def divs(n, start=1): divisors = [] for i in range(start, int(math.sqrt(n) + 1)): if n % i == 0: if n / i == i: divisors.append(i) else: divisors.extend([i, n // i]) return divisors''' # returns the number of factors of a given number if a primes list is given: '''def divn(n, primes): divs_number = 1 for i in primes: if n == 1: return divs_number t = 1 while n % i == 0: t += 1 n //= i divs_number *= t return divs_number''' # returns the leftmost and rightmost positions of x in a given list d(if x isnot present then returns (-1,-1)): '''def flin(d, x, default=-1): left = right = -1 for i in range(len(d)): if d[i] == x: if left == -1: left = i right = i if left == -1: return (default, default) else: return (left, right)''' # returns (b**p)%m '''def modpow(b,p,m): res=1 b=b%m while(p): if p&1: res=(res*b)%m b=(b*b)%m p>>=1 return res''' # if m is a prime this can be used to determine (1//a)%m or modular multiplicative inverse of a number a '''def mod_inv(a,m): return modpow(a,m-2,m)''' # returns the ncr%m for (if m is a prime number) for very large n and r '''def ncr(n,r,m): res=1 if r==0: return 1 if n-r<r: r=n-r p,k=1,1 while(r): res=((res%m)*(((n%m)*mod_inv(r,m))%m))%m n-=1 r-=1 return res''' # returns ncr%m (if m is a prime number and there should be a list fact which stores the factorial values upto n): '''def ncrlis(n,r,m): return (fact[n]*(mod_inv(fact[r],m)*mod_inv(fact[n-r],m))%m)%m''' #factorial list which stores factorial of values upto n: '''mx_lmt=10**5+10 fact=[1 for i in range(mx_lmt)] for i in range(1,mx_lmt): fact[i]=(i*fact[i-1])%mod''' #count xor of numbers from 1 to n: '''def xor1_n(n): d={0:n,1:1,2:n+1,3:0} return d[n&3]''' def ceil(n, k): return n // k + (n % k != 0) def ii(): return int(input()) def mi(): return map(int, input().split()) def li(): return list(map(int, input().split())) def lcm(a, b): return abs(a * b) // math.gcd(a, b) def prr(a, sep=' '): print(sep.join(map(str, a))) def dd(): return defaultdict(int) def ddl(): return defaultdict(list) def ddd(): return defaultdict(defaultdict(int)) # region fastio BUFSIZE = 8192 class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = "x" in file.mode or "r" not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b"\n") + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode("ascii")) self.read = lambda: self.buffer.read().decode("ascii") self.readline = lambda: self.buffer.readline().decode("ascii") sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) input = lambda: sys.stdin.readline().rstrip("\r\n") from collections import defaultdict #from collections import deque #from collections import OrderedDict #from math import gcd #import time #import itertools #import timeit #import random #from bisect import bisect_left as bl #from bisect import bisect_right as br #from bisect import insort_left as il #from bisect import insort_right as ir #from heapq import * #mod=998244353 mod=10**9+7 for _ in range(1): s=input() s+='b' f=0 cnt=0 res=1 for i in range(len(s)): if s[i]=='a': cnt+=1 if s[i]=='b': res*=(1+cnt) res%=mod cnt=0 print(res-1) ```
instruction
0
62,319
0
124,638
Yes
output
1
62,319
0
124,639
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` from functools import reduce s = [len(z)+1 for z in ''.join(y for y in [x for x in input() if x == 'a' or x == 'b']).split('b') if len(z) > 0] print((reduce(lambda x, y: (x*y) % int(1e9+7), s) - 1) % int(1e9+7) if len(s) > 0 else 0) ```
instruction
0
62,320
0
124,640
Yes
output
1
62,320
0
124,641
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` #------------------------------warmup---------------------------- import os import sys from io import BytesIO, IOBase BUFSIZE = 8192 class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = "x" in file.mode or "r" not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b"\n") + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode("ascii")) self.read = lambda: self.buffer.read().decode("ascii") self.readline = lambda: self.buffer.readline().decode("ascii") sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) input = lambda: sys.stdin.readline().rstrip("\r\n") #-------------------game starts now----------------------------------------------------- s=input() n=len(s) c=0 t=0 ans=0 r=0 for i in range(n): if s[i]=='a': t=1 r=(r+1)%1000000007 ans=(ans+c%1000000007)%1000000007 if s[i]=='b' and t==1: c=(c+1)%1000000007 t=0 print((ans+r)%1000000007) ```
instruction
0
62,321
0
124,642
No
output
1
62,321
0
124,643
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` #Code by Sounak, IIESTS #------------------------------warmup---------------------------- import os import sys import math from io import BytesIO, IOBase from fractions import Fraction import collections from itertools import permutations BUFSIZE = 8192 class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = "x" in file.mode or "r" not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b"\n") + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode("ascii")) self.read = lambda: self.buffer.read().decode("ascii") self.readline = lambda: self.buffer.readline().decode("ascii") sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) input = lambda: sys.stdin.readline().rstrip("\r\n") #-------------------game starts now----------------------------------------------------- mod=10**9+7 s=input() n=len(s) count=s.count('a') b=1 curr=0 a=list() for i in s: if i=='a': curr+=1 else: if b>0 and curr>0: a.append(curr) curr=0 b=0 if i=='b': b=1 if b>0 and curr>0: a.append(curr) post=[0]*len(a) if len(a)>0: post[-1]=a[-1] for i in range (len(a)-2,-1,-1): post[i]=post[i+1]+a[i] c=0 for i in range (len(a)-1): c+=(a[i]*post[i+1]) c%=mod #print(count,c) count+=c print(count) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` # call the main method def main(): s = input() a = 1 out = 1 for i in s: if i == 'b': out *= a a = 1 if i == 'a': a = a + 1 out *= a out = out -1 out %= 1000000000 + 7 print(out - 1) if __name__ == "__main__": main() ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. The Nut is upset because he doesn't know how to find the number. Help him. This number should be calculated modulo 10^9 + 7. Input The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters. Output In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7. Examples Input abbaa Output 5 Input baaaa Output 4 Input agaa Output 3 Note In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5]. In the second example, there are 4 possible sequences. [2], [3], [4], [5]. In the third example, there are 3 possible sequences. [1], [3], [4]. Submitted Solution: ``` s=list(input()) p=s.count('a') n=len(s) b=[] mod=10**9+7 for i in range(n): if s[i]=='a': b.append(i) m=len(b) if m<=1: print(p) else: k=0 j=1 #print(b) y=1 for i in range(b[0]+1,b[m-1]): if s[i]=='b': #print(k,j) if b[k]<i<b[j]: #print(m-j) p=(p+m-j)%mod k+=1 y=0 #print(p) if s[i]=='a': j+=1 y=1 #print(j) if k<j and y==0: #print(j) p=(p+m-j)%mod print(p) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Roman and Denis are on the trip to the programming competition. Since the trip was long, they soon got bored, and hence decided to came up with something. Roman invented a pizza's recipe, while Denis invented a string multiplication. According to Denis, the result of multiplication (product) of strings s of length m and t is a string t + s_1 + t + s_2 + … + t + s_m + t, where s_i denotes the i-th symbol of the string s, and "+" denotes string concatenation. For example, the product of strings "abc" and "de" is a string "deadebdecde", while the product of the strings "ab" and "z" is a string "zazbz". Note, that unlike the numbers multiplication, the product of strings s and t is not necessarily equal to product of t and s. Roman was jealous of Denis, since he invented such a cool operation, and hence decided to invent something string-related too. Since Roman is beauty-lover, he decided to define the beauty of the string as the length of the longest substring, consisting of only one letter. For example, the beauty of the string "xayyaaabca" is equal to 3, since there is a substring "aaa", while the beauty of the string "qwerqwer" is equal to 1, since all neighboring symbols in it are different. In order to entertain Roman, Denis wrote down n strings p_1, p_2, p_3, …, p_n on the paper and asked him to calculate the beauty of the string ( … (((p_1 ⋅ p_2) ⋅ p_3) ⋅ … ) ⋅ p_n, where s ⋅ t denotes a multiplication of strings s and t. Roman hasn't fully realized how Denis's multiplication works, so he asked you for a help. Denis knows, that Roman is very impressionable, he guarantees, that the beauty of the resulting string is at most 10^9. Input The first line contains a single integer n (2 ≤ n ≤ 100 000) — the number of strings, wroted by Denis. Next n lines contain non-empty strings p_1, p_2, …, p_n, consisting of lowercase english letters. It's guaranteed, that the total length of the strings p_i is at most 100 000, and that's the beauty of the resulting product is at most 10^9. Output Print exactly one integer — the beauty of the product of the strings. Examples Input 3 a b a Output 3 Input 2 bnn a Output 1 Note In the first example, the product of strings is equal to "abaaaba". In the second example, the product of strings is equal to "abanana". Submitted Solution: ``` ALPH = 'abcdefghijklmnopqrstuvwxyz' MAX = 10 ** 9 def cnt(s): c = {ch : 0 for ch in ALPH} i = 0 while i < len(s): j = i + 1 while j < len(s) and s[i] == s[j]: j += 1 c[s[i]] = max(c[s[i]], j - i) i = j return c def nxt(c, t): nc = cnt(t) for ch in ALPH: if c[ch] and not nc[ch]: nc[ch] = 1 f = 0 while f < len(t) and t[f] == t[0]: f += 1 r = 0 while r < len(t) and t[-1 - r] == t[-1]: r += 1 if t[0] == t[-1]: if f == len(t): nc[t[0]] = max(nc[t[0]], c[t[0]] + (c[t[0]] + 1) * len(t)) elif c[t[0]]: nc[t[0]] = max(nc[t[0]], f + 1 + r) else: nc[t[0]] = max(nc[t[0]], f + (c[t[0]] > 0)) nc[t[-1]] = max(nc[t[-1]], r + (c[t[-1]] > 0)) return {x : min(MAX, y) for x, y in nc.items()} n = int(input()) c = cnt(input()) for i in range(n - 1): c = nxt(c, input()) print(max(c.values())) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Roman and Denis are on the trip to the programming competition. Since the trip was long, they soon got bored, and hence decided to came up with something. Roman invented a pizza's recipe, while Denis invented a string multiplication. According to Denis, the result of multiplication (product) of strings s of length m and t is a string t + s_1 + t + s_2 + … + t + s_m + t, where s_i denotes the i-th symbol of the string s, and "+" denotes string concatenation. For example, the product of strings "abc" and "de" is a string "deadebdecde", while the product of the strings "ab" and "z" is a string "zazbz". Note, that unlike the numbers multiplication, the product of strings s and t is not necessarily equal to product of t and s. Roman was jealous of Denis, since he invented such a cool operation, and hence decided to invent something string-related too. Since Roman is beauty-lover, he decided to define the beauty of the string as the length of the longest substring, consisting of only one letter. For example, the beauty of the string "xayyaaabca" is equal to 3, since there is a substring "aaa", while the beauty of the string "qwerqwer" is equal to 1, since all neighboring symbols in it are different. In order to entertain Roman, Denis wrote down n strings p_1, p_2, p_3, …, p_n on the paper and asked him to calculate the beauty of the string ( … (((p_1 ⋅ p_2) ⋅ p_3) ⋅ … ) ⋅ p_n, where s ⋅ t denotes a multiplication of strings s and t. Roman hasn't fully realized how Denis's multiplication works, so he asked you for a help. Denis knows, that Roman is very impressionable, he guarantees, that the beauty of the resulting string is at most 10^9. Input The first line contains a single integer n (2 ≤ n ≤ 100 000) — the number of strings, wroted by Denis. Next n lines contain non-empty strings p_1, p_2, …, p_n, consisting of lowercase english letters. It's guaranteed, that the total length of the strings p_i is at most 100 000, and that's the beauty of the resulting product is at most 10^9. Output Print exactly one integer — the beauty of the product of the strings. Examples Input 3 a b a Output 3 Input 2 bnn a Output 1 Note In the first example, the product of strings is equal to "abaaaba". In the second example, the product of strings is equal to "abanana". Submitted Solution: ``` t = [0] * 26 def get_k(c): return ord(c) - ord('a') def analyze(s): length_of_str = len(s) pos = 0 beauty_table = [0] * 26 for i in range(1, length_of_str): if s[i] != s[pos]: k = get_k(s[pos]) beauty_table[k] = max(beauty_table[k], i - pos) pos = i k = get_k(s[pos]) beauty_table[k] = max(beauty_table[k], length_of_str - pos) pos = 0 while pos < length_of_str and s[pos] == s[0]: pos += 1 left_beauty = pos pos = length_of_str - 1 while pos > 0 and s[pos] == s[length_of_str - 1]: pos -= 1 right_beauty = length_of_str - pos - 1 return beauty_table, left_beauty, right_beauty r = [] for _ in range(int(input())): p = input() if all(x == p[0] for x in p): # pure k = get_k(p[0]) for i in range(26): if i == k: t[i] = len(p) * (t[i] + 1) + t[i] else: t[i] = min(1, t[i]) else: for i in range(26): t[i] = min(1, t[i]) bt, lb, rb = analyze(p) lk, rk = get_k(p[0]), get_k(p[-1]) if lk == rk: t[lk] = lb + rb + t[lk] else: t[lk], t[rk] = t[lk] + lb, t[rk] + rb for i in range(26): t[i] = max(t[i], bt[i]) # r.append(max(t)) # print('\ntableInfo: ', end= ' ') # for i in range(26): # print('{}:{}/'.format(chr(i + ord('a')), t[i]), end=' ') # print('') # print(' '.join(map(str, r))) print(max(t)) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Roman and Denis are on the trip to the programming competition. Since the trip was long, they soon got bored, and hence decided to came up with something. Roman invented a pizza's recipe, while Denis invented a string multiplication. According to Denis, the result of multiplication (product) of strings s of length m and t is a string t + s_1 + t + s_2 + … + t + s_m + t, where s_i denotes the i-th symbol of the string s, and "+" denotes string concatenation. For example, the product of strings "abc" and "de" is a string "deadebdecde", while the product of the strings "ab" and "z" is a string "zazbz". Note, that unlike the numbers multiplication, the product of strings s and t is not necessarily equal to product of t and s. Roman was jealous of Denis, since he invented such a cool operation, and hence decided to invent something string-related too. Since Roman is beauty-lover, he decided to define the beauty of the string as the length of the longest substring, consisting of only one letter. For example, the beauty of the string "xayyaaabca" is equal to 3, since there is a substring "aaa", while the beauty of the string "qwerqwer" is equal to 1, since all neighboring symbols in it are different. In order to entertain Roman, Denis wrote down n strings p_1, p_2, p_3, …, p_n on the paper and asked him to calculate the beauty of the string ( … (((p_1 ⋅ p_2) ⋅ p_3) ⋅ … ) ⋅ p_n, where s ⋅ t denotes a multiplication of strings s and t. Roman hasn't fully realized how Denis's multiplication works, so he asked you for a help. Denis knows, that Roman is very impressionable, he guarantees, that the beauty of the resulting string is at most 10^9. Input The first line contains a single integer n (2 ≤ n ≤ 100 000) — the number of strings, wroted by Denis. Next n lines contain non-empty strings p_1, p_2, …, p_n, consisting of lowercase english letters. It's guaranteed, that the total length of the strings p_i is at most 100 000, and that's the beauty of the resulting product is at most 10^9. Output Print exactly one integer — the beauty of the product of the strings. Examples Input 3 a b a Output 3 Input 2 bnn a Output 1 Note In the first example, the product of strings is equal to "abaaaba". In the second example, the product of strings is equal to "abanana". Submitted Solution: ``` t = [0] * 26 def get_k(c): return ord(c) - ord('a') def analyze(s): length_of_str = len(s) pos = 0 beauty_table = [0] * 26 for i in range(1, length_of_str): if s[i] != s[pos]: k = get_k(s[pos]) beauty_table[k] = max(beauty_table[k], i - pos) pos = i k = get_k(s[pos]) beauty_table[k] = max(beauty_table[k], length_of_str - pos) pos = 0 while pos < length_of_str and s[pos] == s[0]: pos += 1 left_beauty = pos pos = length_of_str - 1 while pos > 0 and s[pos] == s[length_of_str - 1]: pos -= 1 right_beauty = length_of_str - pos - 1 return beauty_table, left_beauty, right_beauty r = [] for _ in range(int(input())): p = input() if all(x == p[0] for x in p): # pure k = get_k(p[0]) for i in range(26): if i == k: t[i] = len(p) * (t[i] + 1) + t[i] else: t[i] = min(1, t[i]) else: bt, lb, rb = analyze(p) lk, rk = get_k(p[0]), get_k(p[-1]) t[lk] = max(min(1, t[lk]) + lb, t[lk]) t[rk] = max(min(1, t[rk]) + rb, t[rk]) for i in range(26): t[i] = max(t[i], bt[i]) r.append(max(t)) # print('\ntableInfo: ', end= ' ') # for i in range(26): # print('{}:{}/'.format(chr(i + ord('a')), t[i]), end=' ') # print('') # print(' '.join(map(str, r))) print(max(t)) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Roman and Denis are on the trip to the programming competition. Since the trip was long, they soon got bored, and hence decided to came up with something. Roman invented a pizza's recipe, while Denis invented a string multiplication. According to Denis, the result of multiplication (product) of strings s of length m and t is a string t + s_1 + t + s_2 + … + t + s_m + t, where s_i denotes the i-th symbol of the string s, and "+" denotes string concatenation. For example, the product of strings "abc" and "de" is a string "deadebdecde", while the product of the strings "ab" and "z" is a string "zazbz". Note, that unlike the numbers multiplication, the product of strings s and t is not necessarily equal to product of t and s. Roman was jealous of Denis, since he invented such a cool operation, and hence decided to invent something string-related too. Since Roman is beauty-lover, he decided to define the beauty of the string as the length of the longest substring, consisting of only one letter. For example, the beauty of the string "xayyaaabca" is equal to 3, since there is a substring "aaa", while the beauty of the string "qwerqwer" is equal to 1, since all neighboring symbols in it are different. In order to entertain Roman, Denis wrote down n strings p_1, p_2, p_3, …, p_n on the paper and asked him to calculate the beauty of the string ( … (((p_1 ⋅ p_2) ⋅ p_3) ⋅ … ) ⋅ p_n, where s ⋅ t denotes a multiplication of strings s and t. Roman hasn't fully realized how Denis's multiplication works, so he asked you for a help. Denis knows, that Roman is very impressionable, he guarantees, that the beauty of the resulting string is at most 10^9. Input The first line contains a single integer n (2 ≤ n ≤ 100 000) — the number of strings, wroted by Denis. Next n lines contain non-empty strings p_1, p_2, …, p_n, consisting of lowercase english letters. It's guaranteed, that the total length of the strings p_i is at most 100 000, and that's the beauty of the resulting product is at most 10^9. Output Print exactly one integer — the beauty of the product of the strings. Examples Input 3 a b a Output 3 Input 2 bnn a Output 1 Note In the first example, the product of strings is equal to "abaaaba". In the second example, the product of strings is equal to "abanana". Submitted Solution: ``` n = int(input()) s = [] p = "" for i in range(n): s.append(input()) def pd(a,b): s = "" a = list(a) for i in a: s = s + b + i s = s + b return(s) p = pd(s[0],s[1]) for i in range(2,n): p = pd(p,s[i]) s = list(p) c = 1 m = [1] for i in range(len(s) - 1): if s[i] == s[i + 1]: c = c + 1 else: c = 0 m.append(c) m.append(c) print(max(m)) ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Roman and Denis are on the trip to the programming competition. Since the trip was long, they soon got bored, and hence decided to came up with something. Roman invented a pizza's recipe, while Denis invented a string multiplication. According to Denis, the result of multiplication (product) of strings s of length m and t is a string t + s_1 + t + s_2 + … + t + s_m + t, where s_i denotes the i-th symbol of the string s, and "+" denotes string concatenation. For example, the product of strings "abc" and "de" is a string "deadebdecde", while the product of the strings "ab" and "z" is a string "zazbz". Note, that unlike the numbers multiplication, the product of strings s and t is not necessarily equal to product of t and s. Roman was jealous of Denis, since he invented such a cool operation, and hence decided to invent something string-related too. Since Roman is beauty-lover, he decided to define the beauty of the string as the length of the longest substring, consisting of only one letter. For example, the beauty of the string "xayyaaabca" is equal to 3, since there is a substring "aaa", while the beauty of the string "qwerqwer" is equal to 1, since all neighboring symbols in it are different. In order to entertain Roman, Denis wrote down n strings p_1, p_2, p_3, …, p_n on the paper and asked him to calculate the beauty of the string ( … (((p_1 ⋅ p_2) ⋅ p_3) ⋅ … ) ⋅ p_n, where s ⋅ t denotes a multiplication of strings s and t. Roman hasn't fully realized how Denis's multiplication works, so he asked you for a help. Denis knows, that Roman is very impressionable, he guarantees, that the beauty of the resulting string is at most 10^9. Input The first line contains a single integer n (2 ≤ n ≤ 100 000) — the number of strings, wroted by Denis. Next n lines contain non-empty strings p_1, p_2, …, p_n, consisting of lowercase english letters. It's guaranteed, that the total length of the strings p_i is at most 100 000, and that's the beauty of the resulting product is at most 10^9. Output Print exactly one integer — the beauty of the product of the strings. Examples Input 3 a b a Output 3 Input 2 bnn a Output 1 Note In the first example, the product of strings is equal to "abaaaba". In the second example, the product of strings is equal to "abanana". Submitted Solution: ``` import sys from collections import Counter readline = sys.stdin.readline N = int(readline()) S = [readline().strip() for i in range(N)] def calc(s): res = [] last = s[0] cnt = 0 for c in s: if c == last: cnt += 1 else: res.append((last, cnt)) last = c cnt = 1 if cnt > 0: res.append((last, cnt)) return res rr = calc(S[N-1]) if len(rr) > 1: ans = max(x for c, x in rr) c0, x0 = rr[0] c1, x1 = rr[-1] m0 = m1 = 0 for i in range(N-1): s = S[i] for c in s: if c1 == c == c0: ans = max(ans, x0+x1+1) elif c == c0: ans = max(ans, x0+1) elif c == c1: ans = max(ans, x1+1) else: c0, x0 = rr[0] rr0 = calc(S[0]) r = 0 for c, x in rr0: if c0 == c: r = max(r, x) for i in range(1, N-1): rr1 = calc(S[i]) if len(rr1) == 1: c1, x1 = rr1[0] if c0 == c1: r = (r+1)*x1 + r else: r = +(r > 0) else: d0, y0 = rr1[0] d1, y1 = rr1[-1] if c0 != d0: y0 = 0 if c0 != d1: y1 = 0 if r > 0: r = y0 + y1 + 1 else: r = max(y0, y1) ans = (r+1)*x0 + r print(ans) ```
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124,675
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Roman and Denis are on the trip to the programming competition. Since the trip was long, they soon got bored, and hence decided to came up with something. Roman invented a pizza's recipe, while Denis invented a string multiplication. According to Denis, the result of multiplication (product) of strings s of length m and t is a string t + s_1 + t + s_2 + … + t + s_m + t, where s_i denotes the i-th symbol of the string s, and "+" denotes string concatenation. For example, the product of strings "abc" and "de" is a string "deadebdecde", while the product of the strings "ab" and "z" is a string "zazbz". Note, that unlike the numbers multiplication, the product of strings s and t is not necessarily equal to product of t and s. Roman was jealous of Denis, since he invented such a cool operation, and hence decided to invent something string-related too. Since Roman is beauty-lover, he decided to define the beauty of the string as the length of the longest substring, consisting of only one letter. For example, the beauty of the string "xayyaaabca" is equal to 3, since there is a substring "aaa", while the beauty of the string "qwerqwer" is equal to 1, since all neighboring symbols in it are different. In order to entertain Roman, Denis wrote down n strings p_1, p_2, p_3, …, p_n on the paper and asked him to calculate the beauty of the string ( … (((p_1 ⋅ p_2) ⋅ p_3) ⋅ … ) ⋅ p_n, where s ⋅ t denotes a multiplication of strings s and t. Roman hasn't fully realized how Denis's multiplication works, so he asked you for a help. Denis knows, that Roman is very impressionable, he guarantees, that the beauty of the resulting string is at most 10^9. Input The first line contains a single integer n (2 ≤ n ≤ 100 000) — the number of strings, wroted by Denis. Next n lines contain non-empty strings p_1, p_2, …, p_n, consisting of lowercase english letters. It's guaranteed, that the total length of the strings p_i is at most 100 000, and that's the beauty of the resulting product is at most 10^9. Output Print exactly one integer — the beauty of the product of the strings. Examples Input 3 a b a Output 3 Input 2 bnn a Output 1 Note In the first example, the product of strings is equal to "abaaaba". In the second example, the product of strings is equal to "abanana". Submitted Solution: ``` def mult(s, t): f1, l1, cntf1, cntl1, beaut1, n1 = s f2, l2, cntf2, cntl2, beaut2, n2, p = t f3, l3, cntf3, cntl3, beaut3, n3 = 0, 0, 0, 0, beaut1, 0 f3 = f1 l3 = l1 n3 = n2 * (n1 + 1) + n1 if cntf1 == n1 and f1 == f2: cntf3 = n1 * (cntf2 + 1) + cntf2 else: cntf3 = cntf1 if l1 == n1 and l1 == l2: cntl3 = n1 * (cntl2 + 1) + cntl2 else: cntl3 = cntl1 if f1 != l1: if f1 in p: beaut3 = max(beaut3, cntf1 + 1) if l1 in p: beaut3 = max(beaut3, cntl1 + 1) elif cntf1 == n1: beaut3 = max(n1, beaut3) ans = 0 h = 0 for d in p: if d == f1: h += 1 ans = max(ans, h) else: h = 0 ans = max(ans, h) beaut3 = max(beaut3, n1 * (ans + 1) + ans) else: if f1 in p: beaut3 = max(beaut3, 1 + cntf1 + cntl1) else: beaut3 = max(beaut3, cntf1, cntl1) return [f3, l3, cntf3, cntl3, beaut3, n3] n = int(input()) p = [] for i in range(n): p.append(input()) pp = [] for s in p: f = s[0] l = s[-1] cntf = 0 cntl = 0 beaut = 1 hep = 1 for i in s: if i == f: cntf += 1 else: break for i in s[::-1]: if i == l: cntl += 1 else: break for i in range(1, len(s)): if s[i] == s[i - 1]: hep += 1 else: beaut = max(beaut, hep) hep = 1 beaut = max(beaut, hep) pp.append([f, l, cntf, cntl, beaut, len(s), s]) p = pp[::-1] lasts = p[0][:-1] for i in range(1, len(p)): lasts = mult(lasts, p[i]) print(lasts[-2]) ```
instruction
0
62,338
0
124,676
No
output
1
62,338
0
124,677
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a string s consisting of lowercase English letters and a number k. Let's call a string consisting of lowercase English letters beautiful if the number of occurrences of each letter in that string is divisible by k. You are asked to find the lexicographically smallest beautiful string of length n, which is lexicographically greater or equal to string s. If such a string does not exist, output -1. A string a is lexicographically smaller than a string b if and only if one of the following holds: * a is a prefix of b, but a ≠ b; * in the first position where a and b differ, the string a has a letter that appears earlier in the alphabet than the corresponding letter in b. Input The first line contains a single integer T (1 ≤ T ≤ 10 000) — the number of test cases. The next 2 ⋅ T lines contain the description of test cases. The description of each test case consists of two lines. The first line of the description contains two integers n and k (1 ≤ k ≤ n ≤ 10^5) — the length of string s and number k respectively. The second line contains string s consisting of lowercase English letters. It is guaranteed that the sum of n over all test cases does not exceed 10^5. Output For each test case output in a separate line lexicographically smallest beautiful string of length n, which is greater or equal to string s, or -1 if such a string does not exist. Example Input 4 4 2 abcd 3 1 abc 4 3 aaaa 9 3 abaabaaaa Output acac abc -1 abaabaaab Note In the first test case "acac" is greater than or equal to s, and each letter appears 2 or 0 times in it, so it is beautiful. In the second test case each letter appears 0 or 1 times in s, so s itself is the answer. We can show that there is no suitable string in the third test case. In the fourth test case each letter appears 0, 3, or 6 times in "abaabaaab". All these integers are divisible by 3.
instruction
0
62,511
0
125,022
Tags: binary search, brute force, constructive algorithms, greedy, strings Correct Solution: ``` gans = [] for _ in range(int(input())): n, k = map(int, input().split()) u = list(input()) for i in range(n): u[i] = ord(u[i]) - ord('a') z = [] for i in range(26): z.append([]) z[-1].append(0) z[u[0]][0] += 1 z[u[0]][0] %= k for i in range(1, n): for j in range(26): z[j].append(z[j][i - 1]) z[u[i]][i] += 1 z[u[i]][i] %= k for i in range(n - 1, -1, -1): sm = 0 for j in range(26): sm += (k - z[j][i]) % k if sm % k == (n - i - 1) % k and sm <= n - i - 1: if i == n - 1: ans = [] for r in range(n): ans.append(chr(u[r] + ord('a'))) gans.append(''.join(ans)) break ans = u[:i + 1] if sm + k > n - i - 1 or u[i + 1] == ord('z') - ord('a'): for j in range(u[i + 1] + 1, 26): if z[j][i] != 0: ans.append(j) z[j][i] += 1 z[j][i] %= k break else: continue else: ans.append(u[i + 1] + 1) z[u[i + 1] + 1][i] += 1 z[u[i + 1] + 1][i] %= k s = [] for j in range(26): for r in range((k - z[j][i]) % k): s.append(j) for j in range(n - len(ans) - len(s)): ans.append(0) ans += s for j in range(len(ans)): ans[j] = chr(ans[j] + ord('a')) gans.append(''.join(ans)) break else: if n % k == 0 and u[0] != z: ans = [u[0] + 1] for i in range(n - k): ans.append(0) for i in range(k - 1): ans.append(u[0] + 1) for i in range(n): ans[i] = chr(ans[i] + ord('a')) gans.append(''.join(ans)) else: gans.append(str(-1)) print('\n'.join(gans)) ```
output
1
62,511
0
125,023
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a string s consisting of lowercase English letters and a number k. Let's call a string consisting of lowercase English letters beautiful if the number of occurrences of each letter in that string is divisible by k. You are asked to find the lexicographically smallest beautiful string of length n, which is lexicographically greater or equal to string s. If such a string does not exist, output -1. A string a is lexicographically smaller than a string b if and only if one of the following holds: * a is a prefix of b, but a ≠ b; * in the first position where a and b differ, the string a has a letter that appears earlier in the alphabet than the corresponding letter in b. Input The first line contains a single integer T (1 ≤ T ≤ 10 000) — the number of test cases. The next 2 ⋅ T lines contain the description of test cases. The description of each test case consists of two lines. The first line of the description contains two integers n and k (1 ≤ k ≤ n ≤ 10^5) — the length of string s and number k respectively. The second line contains string s consisting of lowercase English letters. It is guaranteed that the sum of n over all test cases does not exceed 10^5. Output For each test case output in a separate line lexicographically smallest beautiful string of length n, which is greater or equal to string s, or -1 if such a string does not exist. Example Input 4 4 2 abcd 3 1 abc 4 3 aaaa 9 3 abaabaaaa Output acac abc -1 abaabaaab Note In the first test case "acac" is greater than or equal to s, and each letter appears 2 or 0 times in it, so it is beautiful. In the second test case each letter appears 0 or 1 times in s, so s itself is the answer. We can show that there is no suitable string in the third test case. In the fourth test case each letter appears 0, 3, or 6 times in "abaabaaab". All these integers are divisible by 3.
instruction
0
62,512
0
125,024
Tags: binary search, brute force, constructive algorithms, greedy, strings Correct Solution: ``` import sys, math, itertools, random, bisect from collections import defaultdict INF = sys.maxsize def get_ints(): return map(int, sys.stdin.readline().strip().split()) def get_array(): return list(map(int, sys.stdin.readline().strip().split())) def input(): return sys.stdin.readline().strip() mod = 10**9 + 7 def get(x,k): return (k - x%k) % k for _ in range(int(input())): n,k = get_ints() s = input() if n%k!=0: print(-1) else: cnt = [0]*26 for i in s: cnt[ord(i)-ord('a')] += 1 tot = 0 flag = 1 for i in range(26): tot += get(cnt[i],k) if tot==0: print(s) flag = 0 for i in range(n-1,-1,-1): if not flag: break tot -= get(cnt[ord(s[i])-ord('a')], k) cnt[ord(s[i])-ord('a')] -= 1 tot += get(cnt[ord(s[i])-ord('a')], k) for j in range(ord(s[i])-ord('a')+1, 26): lst_tot = tot tot -= get(cnt[j],k) cnt[j] += 1 tot += get(cnt[j],k) if tot <= n-i-1: print(s[:i],end="") print(chr(ord('a')+j),end="") rem = "" rem += 'a'*(n-i-1 - tot) for w in range(26): f = get(cnt[w],k) rem += chr(ord('a')+w)*f # rem = "".join(sorted(rem)) print(rem) flag = 0 break cnt[j] -= 1 tot = lst_tot ```
output
1
62,512
0
125,025