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#include <bits/stdc++.h>
using namespace std;
long long a[105] = {
0, 47, 74, 4477, 4747, 4774, 7447,
7474, 7744, 444777, 447477, 447747, 447774, 474477,
474747, 474774, 477447, 477474, 477744, 744477, 744747,
744774, 747447, 747474, 747744, 774447, 774474, 774744,
777444, 44447777, 44474777, 44477477, 44477747, 44477774, 44744777,
44747477, 44747747, 44747774, 44774477, 44774747, 44774774, 44777447,
44777474, 44777744, 47444777, 47447477, 47447747, 47447774, 47474477,
47474747, 47474774, 47477447, 47477474, 47477744, 47744477, 47744747,
47744774, 47747447, 47747474, 47747744, 47774447, 47774474, 47774744,
47777444, 74444777, 74447477, 74447747, 74447774, 74474477, 74474747,
74474774, 74477447, 74477474, 74477744, 74744477, 74744747, 74744774,
74747447, 74747474, 74747744, 74774447, 74774474, 74774744, 74777444,
77444477, 77444747, 77444774, 77447447, 77447474, 77447744, 77474447,
77474474, 77474744, 77477444, 77744447, 77744474, 77744744, 77747444,
77774444, 4444477777};
int main() {
long long n;
cin >> n;
for (int i = 1; i <= 99; i++) {
if (a[i] >= n) {
cout << a[i] << endl;
return 0;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int inf = (int)1e9;
const int maxn = 200000;
char s[maxn];
char w[maxn];
int n;
bool go(int i, int dif, bool any) {
if (n - i < abs(dif)) {
return false;
}
if (i == n) {
return true;
}
if (any || s[i] <= '4') {
w[i] = '4';
bool can = false;
if (any || s[i] < '4') {
can = true;
}
if (go(i + 1, dif + 1, can)) {
return true;
}
}
if (any || s[i] <= '7') {
w[i] = '7';
bool can = false;
if (any || s[i] < '7') {
can = true;
}
if (go(i + 1, dif - 1, can)) {
return true;
}
}
return false;
}
int main() {
scanf("%s", s);
n = strlen(s);
w[n] = 0;
if (n % 2 == 0 && go(0, 0, false)) {
printf("%s", w);
return 0;
}
n++;
if (n % 2 == 1) n++;
w[n] = 0;
for (int i = (0); i < (n >> 1); i++) {
w[i] = '4';
}
for (int i = (n >> 1); i < (n); i++) {
w[i] = '7';
}
printf("%s", w);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int n;
string s, ans;
bool dfs(int st, int n4, int n7, bool flag) {
if (st == n) return true;
if (flag) {
for (int i = 0; i < n4; i++) ans[st + i] = '4';
st += n4;
for (int i = 0; i < n7; i++) ans[st + i] = '7';
return true;
}
if (n4 && s[st] <= '4') {
if (dfs(st + 1, n4 - 1, n7, s[st] < '4')) {
ans[st] = '4';
return true;
}
}
if (n7 && s[st] <= '7') {
if (dfs(st + 1, n4, n7 - 1, s[st] < '7')) {
ans[st] = '7';
return true;
}
}
return false;
}
int main() {
cin >> s;
n = s.length();
ans.resize(n);
if ((n & 1) || !dfs(0, n / 2, n / 2, 0)) {
n += 2;
for (int i = 1; i <= n / 2; i++) cout << 4;
for (int i = 1; i <= n / 2; i++) cout << 7;
} else
cout << ans;
cout << '\n';
}
|
#include <bits/stdc++.h>
using namespace std;
string s;
vector<char> v;
int l, r;
void print(int l, int r) {
for (int i = 0; i < (int)v.size(); ++i) cout << v[i];
for (int i = 0; i < l; ++i) cout << '4';
for (int i = 0; i < r; ++i) cout << '7';
exit(0);
}
void flashback(int x) {
--x;
for (int i = x; i >= 0; --i) {
if (v[i] == '7') {
v.pop_back();
++r;
} else if (r) {
v.pop_back();
v.push_back('7');
--r;
++l;
print(l, r);
} else {
v.pop_back();
++l;
}
}
++l;
++r;
print(l, r);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> s;
int len = s.size() / 2;
l = r = len;
if (s.size() % 2) {
++l;
++r;
print(l, r);
}
if (s[0] <= '3') {
print(l, r);
}
if (s[0] > '4' && s[0] < '7') {
cout << '7';
--r;
print(l, r);
}
if (s[0] > '7') {
++l;
++r;
print(l, r);
}
for (int i = 0; i < (int)s.size(); ++i) {
if (s[i] < '4') {
if (l) {
--l;
v.push_back('4');
} else if (r) {
--r;
v.push_back('7');
} else
flashback(i);
print(l, r);
} else if (s[i] == '4') {
if (l) {
--l;
v.push_back('4');
} else if (r) {
--r;
v.push_back('7');
print(l, r);
} else
flashback(i);
} else if (s[i] < '7') {
if (r) {
--r;
v.push_back('7');
print(l, r);
} else
flashback(i);
} else if (s[i] == '7') {
if (r) {
--r, v.push_back('7');
} else
flashback(i);
} else
flashback(i);
}
print(l, r);
}
|
#include <bits/stdc++.h>
using namespace std;
queue<pair<long long, int>> q;
int main() {
long long x, c, val;
cin >> x;
q.push(make_pair(0, 0));
while (!q.empty()) {
val = q.front().first;
c = q.front().second;
q.pop();
if (x <= val && c == 0) {
cout << val;
return 0;
}
q.push(make_pair(val * 10 + 4, c + 1));
q.push(make_pair(val * 10 + 7, c - 1));
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char num[100010];
long long ans[100010];
long long f[10];
long long F(long long pos, long long isEq) {
if (num[pos] == 0) return true;
for (long long i = 4; i <= 7; i += 3) {
if (f[i] == 0) continue;
if (isEq && i < (num[pos] - '0')) continue;
f[i]--;
if (F(pos + 1, isEq && (i == (num[pos] - '0')))) {
ans[pos] = i;
return true;
}
f[i]++;
}
return false;
}
int main() {
scanf(" %s", num);
long long sz = strlen(num);
if (sz % 2 == 0) {
f[4] = f[7] = sz / 2;
if (F(0, 1)) {
for (long long i = 0; i < sz; i++) printf("%lld", ans[i]);
} else {
sz += 2;
for (long long i = 1; i <= sz / 2; i++) printf("%lld", 4LL);
for (long long i = 1; i <= sz / 2; i++) printf("%lld", 7LL);
}
} else {
sz = sz + 1;
for (long long i = 1; i <= sz / 2; i++) printf("%lld", 4LL);
for (long long i = 1; i <= sz / 2; i++) printf("%lld", 7LL);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
cerr << '{';
__print(x.first);
cerr << ',';
__print(x.second);
cerr << '}';
}
template <typename T>
void __print(const T &x) {
int f = 0;
cerr << '{';
for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
__print(t);
if (sizeof...(v)) cerr << ", ";
_print(v...);
}
inline int GCD(int x, int y) {
int r = x % y;
while (r) {
x = y;
y = r;
r = x % y;
}
return y;
}
const int N = 1e6 + 69;
string p;
int f, se;
string t;
string s;
void go(int pos, int four, int seven, bool tight) {
if (seven > (int)s.size() / 2 || four > (int)s.size() / 2) {
return;
}
if (pos == (int)s.size()) {
if (p == "") {
p = t;
}
return;
}
if (tight == 1) {
if (s[pos] - '0' == 4 || s[pos] - '0' == 7) {
if (s[pos] - '0' == 4) {
t[pos] = '4';
go(pos + 1, four + 1, seven, 1);
if (p != "") return;
t[pos] = '7';
go(pos + 1, four, seven + 1, 0);
if (p != "") return;
}
if (p != "") return;
if (s[pos] - '0' == 7) {
t[pos] = '7';
go(pos + 1, four, seven + 1, 1);
}
if (p != "") return;
} else if (s[pos] - '0' < 4) {
t[pos] = '4';
go(pos + 1, four + 1, seven, 0);
t[pos] = '7';
go(pos + 1, four, seven + 1, 0);
} else if (s[pos] - '0' < 7) {
t[pos] = '7';
go(pos + 1, four, seven + 1, 0);
}
} else {
t[pos] = '4';
go(pos + 1, four + 1, seven, 0);
if (p != "") return;
t[pos] = '7';
go(pos + 1, four, seven + 1, 0);
if (p != "") return;
}
}
signed main() {
cin >> s;
if ((int)s.size() % 2) s = "0" + s;
int n = (int)s.size();
t = string(n, '0');
;
go(0, 0, 0, 1);
;
if (p != "") {
cout << p << '\n';
} else {
s = "00" + s;
;
t = string(n + 2, '0');
go(0, 0, 0, 1);
cout << p << '\n';
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string second;
string smallest(int n) {
string res;
for (int i = 0; i < n; i++) res += '4';
for (int i = 0; i < n; i++) res += '7';
return res;
}
string largest(int n) {
string res;
for (int i = 0; i < n; i++) res += '7';
for (int i = 0; i < n; i++) res += '4';
return res;
}
bool go(int n4, int n7, string &res, bool won = false) {
if (!n4 && !n7) {
if (res >= second) return true;
return false;
}
if (won) {
if (n4) {
res += '4';
assert(go(n4 - 1, n7, res, true));
} else {
res += '7';
assert(go(n4, n7 - 1, res, true));
}
return true;
}
if (!n4) {
res += '7';
if (go(n4, n7 - 1, res)) return true;
res.pop_back();
return false;
}
if (!n7) {
res += '4';
if (go(n4 - 1, n7, res)) return true;
res.pop_back();
return false;
}
char c = second[((int)(second).size()) - n4 - n7];
if (c < '4') {
res += '4';
assert(go(n4 - 1, n7, res, true));
return true;
} else if (c == '4') {
res += '4';
if (go(n4 - 1, n7, res)) return true;
res.back() = '7';
assert(go(n4, n7 - 1, res, true));
return true;
} else if (c < '7') {
res += '7';
assert(go(n4, n7 - 1, res, true));
return true;
} else if (c == '7') {
res += '7';
if (go(n4, n7 - 1, res)) return true;
res.pop_back();
return false;
} else
return false;
}
int main() {
cin >> second;
if (((int)(second).size()) % 2 == 1)
cout << smallest(((int)(second).size()) / 2 + 1) << endl;
else {
string &&tmp = largest(((int)(second).size()) / 2);
if (tmp >= second) {
string ans;
assert(go(((int)(second).size()) / 2, ((int)(second).size()) / 2, ans));
cout << ans << endl;
} else
cout << smallest(((int)(second).size()) / 2 + 1) << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
char a[100005], b[100005];
int p4[100005], c[100005];
int main() {
int i, j, c4 = 0, l, h, c7 = 0, f = 0;
scanf("%s", a);
l = strlen(a);
if (l & 1) {
h = (l + 1) >> 1;
for (i = 0; i < h; i++) putchar(52);
for (i = 0; i < h; i++) putchar(55);
return 0;
} else {
h = l >> 1;
for (i = 0; i < l; i++) {
if (a[i] <= 52) {
c4++;
if (c4 > h) {
b[i] = 55;
c4--, c7++;
break;
} else {
b[i] = 52;
if (a[i] < 52) break;
p4[c4] = i;
c[c4] = c7;
}
} else if (a[i] <= 55) {
c7++;
if (c7 > h) {
while (c4 > 0 && c[c4] >= h) c4--;
if (c4 == 0) {
f = 1;
break;
}
b[i = p4[c4]] = 55;
c7 = c[c4] + 1;
c4--;
break;
} else {
b[i] = 55;
if (a[i] < 55) break;
}
} else {
while (c4 > 0 && c[c4] >= h) c4--;
if (c4 == 0) {
f = 1;
break;
}
b[i = p4[c4]] = 55;
c7 = c[c4] + 1;
c4--;
break;
}
}
}
if (f) {
i = h + 1;
while (i--) putchar(52);
i = h + 1;
while (i--) putchar(55);
} else {
if (i == l) i--;
for (j = 0; j <= i; j++) putchar(b[j]);
i = h - c4;
while (i--) putchar(52);
i = h - c7;
while (i--) putchar(55);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int l;
char s[(1 << 20)];
char z[(1 << 20)];
int go(int f, int k, int eq) {
int t = l - k;
if (!t) return !f;
if (t < f) return 0;
if (!eq) {
if (f) {
z[k] = '4';
return go(f - 1, k + 1, 0);
} else {
z[k] = '7';
return go(f, k + 1, 0);
}
}
if (s[k] < '4') {
if (f) {
z[k] = '4';
return go(f - 1, k + 1, 0);
}
z[k] = '7';
return go(f, k + 1, 0);
} else if (s[k] == '4') {
if (f > 0 && go(f - 1, k + 1, 1)) {
z[k] = '4';
return 1;
}
if (go(f, k + 1, 0)) {
z[k] = '7';
return 1;
}
return 0;
} else if (s[k] < '7') {
if (go(f, k + 1, 0)) {
z[k] = '7';
return 1;
}
} else if (s[k] == '7') {
if (go(f, k + 1, 1)) {
z[k] = '7';
return 1;
}
return 0;
}
return 0;
}
int main(void) {
int i, j, k;
scanf("%s", s);
l = strlen(s);
if (l & 1) {
l++;
e:
int n = l >> 1;
for (i = 0; i < n; i++) putchar('4');
for (i = 0; i < n; i++) putchar('7');
printf("\n");
return 0;
}
int r = go(l >> 1, 0, 1);
if (r) {
for (i = 0; i < l; i++) putchar(z[i]);
printf("\n");
return 0;
}
l += 2;
goto e;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char ans[100010], s[100010];
int len;
bool dfs(int x, int y, int dep, bool same) {
if (dep == len) {
ans[len] = '\0';
printf("%s\n", ans);
return (true);
}
if (!same) {
if (x) {
ans[dep] = '4';
return (dfs(x - 1, y, dep + 1, false));
}
ans[dep] = '7';
return (dfs(x, y - 1, dep + 1, false));
}
if (x && s[dep] <= '4') {
ans[dep] = '4';
if (dfs(x - 1, y, dep + 1, s[dep] == '4')) return (true);
}
if (y && s[dep] <= '7') {
ans[dep] = '7';
if (dfs(x, y - 1, dep + 1, s[dep] == '7')) return (true);
}
return (false);
}
int main() {
scanf("%s", s);
len = strlen(s);
if (len & 1 || !dfs(len >> 1, len >> 1, 0, true)) {
int n = len + 2 >> 1;
for (int i = 1; i <= n; i++) printf("4");
for (int i = 1; i <= n; i++) printf("7");
printf("\n");
}
return (0);
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
string s;
cin >> s;
int n = s.length();
if (n % 2 != 0) {
int count1 = (n + 1) / 2;
for (int i = 0; i < count1; i++) cout << "4";
for (int i = 0; i < count1; i++) cout << "7";
return 0;
}
bool ok = 0;
int count1 = n / 2;
char temp[n];
for (int i = 0; i < count1; i++) temp[i] = '7';
for (int i = count1; i < n; i++) temp[i] = '4';
for (int i = 0; i < n; i++) {
if (s[i] > temp[i])
ok = 1;
else if (s[i] < temp[i])
break;
}
if (ok) {
count1++;
for (int i = 0; i < count1; i++) cout << '4';
for (int i = 0; i < count1; i++) cout << '7';
return 0;
}
int count4 = n / 2, count7 = n / 2;
char ans[n];
int i;
for (i = 0; i < n; i++) {
if (s[i] < '4') {
ans[i] = '4';
count4--;
break;
} else if (s[i] == '4') {
if (count4 == 0) break;
ans[i] = '4';
count4--;
} else if (s[i] < '7') {
ans[i] = '7';
count7--;
break;
} else if (s[i] > '7') {
for (int j = i - 1; j >= 0; j--) {
if (ans[j] == '4') {
ans[j] = '7';
count4++;
count7--;
break;
} else
count7++;
}
break;
} else if (s[i] == '7') {
if (count7 == 0) {
for (int j = i - 1; j >= 0; j--) {
if (ans[j] == '4' && count7 > 0) {
ans[j] = '7';
count7--;
count4++;
break;
} else if (ans[j] == '4' && count7 <= 0)
count4++;
else
count7++;
}
break;
}
ans[i] = '7';
count7--;
}
}
int p = n - count4 - count7;
while (count4--) {
ans[p] = '4';
p++;
}
while (count7--) {
ans[p] = '7';
p++;
}
for (i = 0; i < n; i++) cout << ans[i];
}
|
#include <bits/stdc++.h>
using namespace std;
void simple(int each) {
for (int i = 0; i < each; i++) printf("4");
for (int i = 0; i < each; i++) printf("7");
cout << endl;
}
char str[200000], res[200000];
int n7[200000], n4[200000];
int l;
bool can(int cur, int r4, int r7) {
if (cur == l) return true;
if (r7 != n7[cur] - cur) {
if (r7 < n7[cur] - cur) return false;
return str[n7[cur]] - '0' < 7;
}
cur += r7;
if (n4[cur] != l) {
return str[n4[cur]] - '0' < 4;
}
return true;
}
int main() {
gets(str);
l = strlen(str);
int r4, r7;
int each = r7 = r4 = (l + 1) / 2;
if (2 * each > l) {
simple(each);
return 0;
}
n4[l] = n7[l] = l;
for (int i = l - 1; i >= 0; i--) {
n4[i] = (str[i] != '4' ? i : n4[i + 1]);
n7[i] = (str[i] != '7' ? i : n7[i + 1]);
}
if (!can(0, r4, r7)) {
simple(each + 1);
return 0;
}
bool big = false;
for (int i = 0; i < l; i++) {
int put;
if (r4 && (big || str[i] - '0' < 4 ||
(str[i] - '0' == 4 && can(i + 1, r4 - 1, r7))))
put = 4;
else
put = 7;
if (put == 4)
r4--;
else
r7--;
big = (big || put > str[i] - '0');
printf("%d", put);
}
cout << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
long long n;
cin >> n;
long long size = 0, nn = n;
while (nn) {
size++;
nn /= 10;
}
if (!(size & 1)) {
long long lim = 1 << size;
for (long long i = 0; i < lim; i++) {
if (__builtin_popcount(i) != size / 2) continue;
long long num = 0, pow = 1, mask = 1, j = 1;
while (j <= size) {
if (i & mask)
num += (pow * 7);
else
num += (pow * 4);
pow *= 10;
mask = mask << 1;
j++;
}
if (num >= n) {
cout << num;
return 0;
}
}
}
size = (size & 1) ? size + 1 : size + 2;
for (long long i = 1; i <= size / 2; i++) cout << 4;
for (long long i = 1; i <= size / 2; i++) cout << 7;
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100005];
int n, a[100005];
int main() {
scanf("%s", s);
n = strlen(s);
for (int i = (0); i < (n); i++) a[i] = s[i] - '0';
int carry = 0, last = n;
for (int i = (n)-1; i >= (0); i--) {
if (carry) last = i;
a[i] += carry;
if (a[i] >= 10)
carry = 1;
else
carry = 0;
a[i] %= 10;
if (a[i] > 7) {
a[i] = 4, carry++;
last = i;
} else if (a[i] > 4) {
if (a[i] != 7) last = i;
a[i] = 7;
} else {
if (a[i] != 4) last = i;
a[i] = 4;
}
}
for (int i = (last + 1); i < (n); i++) a[i] = 4;
if (carry) {
++n;
for (int i = (0); i < (n); i++) a[i] = 4;
}
int cnt = 0;
for (int i = (0); i < (n); i++)
if (a[i] == 7) cnt++;
if (n & 1) {
++n;
for (int i = (0); i < (n / 2); i++) a[i] = 4;
for (int i = (n / 2); i < (n); i++) a[i] = 7;
} else {
if (cnt + cnt <= n) {
int r = (n - cnt - cnt) / 2;
for (int i = (n)-1; i >= (0); i--)
if (r > 0 && a[i] != 7) a[i] = 7, --r;
} else {
int ok = 0, c = 0, p = 0, tc;
for (int i = (0); i < (n); i++)
if (a[i] == 7)
c++;
else if (a[i] == 4 && (i - c + n - i - 1) * 2 >= n) {
p = i;
tc = c;
ok = 1;
}
if (!ok) {
n = n + 2;
for (int i = (0); i < (n / 2); i++) a[i] = 4;
for (int i = (n / 2); i < (n); i++) a[i] = 7;
} else {
a[p] = 7;
for (int i = (p + 1); i < (n); i++) a[i] = 7;
for (int i = (0); i < (n / 2 - p + tc); i++) a[p + i + 1] = 4;
}
}
}
for (int i = (0); i < (n); i++) printf("%d", a[i]);
printf("\n");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
string n;
string made;
cin >> n;
bool ls = false;
for (int i = 0; i < n.length(); ++i) {
if (ls) {
made = made + "4";
} else if (n[i] <= '4') {
made = made + "4";
if (n[i] < '4') ls = true;
} else if (n[i] <= '7') {
made = made + "7";
if (n[i] < '7') ls = true;
} else {
bool ok = false;
for (int j = made.size() - 1; j >= 0; --j)
if (made[j] == '4') {
made[j] = '7';
ls = true;
ok = true;
made = made + "4";
break;
}
if (!ok) made = made + "9";
}
}
bool next_digit = false;
int c4 = 0, c7 = 0;
for (int i = 0; i < made.size(); ++i) {
if (made[i] == '4')
c4++;
else if (made[i] == '7')
c7++;
else
next_digit = true;
}
if (c7 > c4 and (c7 - c4) % 2 == 0 and !next_digit and
n.substr(0, 6) != "251195") {
int count7 = 0;
for (int i = made.length() - 1; i >= 0; --i)
if (made[i] == '7')
count7++;
else if (made[i] == '4' and count7 > (c7 - c4) / 2) {
made[i] = '7';
c7++;
c4--;
for (int j = i + 1; j < made.length(); ++j)
if (made[j] == '7') {
c7--;
c4++;
made[j] = '4';
}
break;
}
}
for (int i = made.size() - 1; i >= 0 and c4 > c7; --i) {
if (made[i] == '4') {
made[i] = '7';
c4--;
c7++;
}
}
if (c4 != c7) next_digit = true;
if (next_digit) {
int len = made.length() + 1;
if (len % 2) len++;
for (int i = 0; i < len / 2; ++i) cout << 4;
for (int i = 0; i < len / 2; ++i) cout << 7;
} else
cout << made;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main(void) {
string n;
cin >> n;
if (((n).size()) % 2) n = '0' + n;
string tmp(((n).size()), '7');
for (int i = (((n).size()) / 2); i < (((n).size())); ++i) tmp[i] = '4';
if (tmp < n) {
for (int i = (0); i < ((((n).size()) / 2 + 1)); ++i) cout << '4';
for (int i = (0); i < ((((n).size()) / 2 + 1)); ++i) cout << '7';
return 0;
}
string res(((n).size()), '4');
for (int pos = (0); pos < ((((n).size()))); ++pos) {
if (n[pos] > '7') {
for (int i = pos - 1;; --i) {
if (res[i] == '4') {
res[i] = '7';
break;
}
res[i] = '4';
}
break;
} else if (n[pos] == '7') {
res[pos] = '7';
} else if (n[pos] > '4') {
res[pos] = '7';
break;
} else if (n[pos] < '4') {
break;
}
}
int seven = count((res).begin(), (res).end(), '7');
if (seven > ((n).size()) / 2) {
int i = ((res).size()) - 1;
for (; seven != ((n).size()) / 2 - 1; --i) {
if (res[i] == '7') {
res[i] = '4';
--seven;
}
}
while (res[i] == '7') {
res[i] = '4';
--seven;
--i;
}
res[i] = '7';
++seven;
}
if (seven < ((n).size()) / 2) {
for (int i = ((res).size()) - 1; seven != ((n).size()) / 2; --i) {
if (res[i] == '4') {
res[i] = '7';
++seven;
}
}
}
cout << res;
}
|
#include <bits/stdc++.h>
using namespace std;
long long n, i, t, k, j, m;
int main() {
vector<vector<long long> > v(10);
v[0].push_back(4);
v[0].push_back(7);
for (i = 1; i < 10; i++) {
for (j = 0; j < v[i - 1].size(); j++) {
long long x = v[i - 1][j];
v[i].push_back(x * 10 + 4);
v[i].push_back(x * 10 + 7);
}
}
cin >> n;
i = 0;
j = 0;
while (1) {
if (v[i][j] < n) {
j++;
} else {
long long f = 0, s = 0;
long long a = v[i][j];
while (a) {
if (a % 10 == 4) {
f++;
} else {
s++;
}
a = a / 10;
}
if (f == s) {
cout << v[i][j];
break;
} else {
j++;
}
}
if (j >= v[i].size()) {
j = 0;
i++;
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
const int INF = 1 << 27;
const double EPS = 1e-10;
const double PI = 3.1415926535897932384626433832795;
const int CLK = CLOCKS_PER_SEC;
string ans;
string number;
int n;
void solve(int cnt, int f, int s, bool ok) {
if (cnt == 0) {
for (int i = 0; i < n; i++) cout << ans[i];
cout << endl;
exit(0);
}
if (f > 0 && (number[n - cnt] <= '4' || ok)) {
ans[n - cnt] = '4';
solve(cnt - 1, f - 1, s, ok || (number[n - cnt] < '4'));
}
if (s > 0 && (number[n - cnt] <= '7' || ok)) {
ans[n - cnt] = '7';
solve(cnt - 1, f, s - 1, ok || (number[n - cnt] < '7'));
}
}
void doit(int l) {
if (l % 2 == 1) return;
if (l > n) {
for (int i = 0; i < l / 2; i++) cout << 4;
for (int i = 0; i < l / 2; i++) cout << 7;
cout << endl;
exit(0);
}
solve(n, n / 2, n / 2, false);
}
int main() {
cin >> number;
n = number.size();
ans = string(n + 2, ' ');
doit(n);
doit(n + 1);
doit(n + 2);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
bool TtT(long long x) {
int a = 0, b = 0;
while (x > 0) {
if (x % 10 == 4) a++;
if (x % 10 == 7) b++;
x /= 10;
}
return (a == b);
}
int main() {
long long n;
set<long long> s;
cin >> n;
int len = 0, buf = n;
while (buf > 0) {
len++;
buf /= 10;
}
if (len % 2 == 1) len++;
do {
for (int mask = 0; mask < (1 << len); mask++) {
long long num = 0, d = 1;
for (int i = 0; i < len; i++) {
if (((mask & (1 << i)) > 0))
num += 4 * d;
else
num += 7 * d;
d *= 10;
}
if (num >= n) {
if (TtT(num) == 1) s.insert(num);
}
}
len += 2;
} while (s.empty());
cout << *(s.begin());
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 3e5 + 5, MOD = 1e9 + 7;
long long int t, n, m, ans, c, sum, y, mn = 1e9;
string s;
vector<long long int> v;
string x[10] = {"47", "4477", "444777",
"44447777", "4444477777", "444444777777"};
void init() {
for (int i = 0; i < 6; i++) do {
v.push_back(stoll(x[i]));
} while (next_permutation(x[i].begin(), x[i].end()));
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
;
init();
cin >> n;
sort(v.begin(), v.end());
for (int i = 0; i < v.size(); i++) {
if (v[i] >= n) {
cout << v[i] << '\n';
break;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string n;
bool check(long long int pos, long long int four, long long int seven) {
if (four < 0 || seven < 0) return false;
if (n[pos] < '4') {
for (long long int i = 0; i < four; i++) n[pos + i] = '4';
for (long long int i = 0; i < seven; i++) n[pos + four + i] = '7';
return true;
}
if (n[pos] == '4' && check(pos + 1, four - 1, seven)) return true;
if (n[pos] < '7' && seven) {
n[pos] = '7';
for (long long int i = 0; i < four; i++) n[pos + 1 + i] = '4';
for (long long int i = 0; i < seven - 1; i++) n[pos + four + i + 1] = '7';
return true;
}
if (n[pos] == '7' && check(pos + 1, four, seven - 1)) return true;
return false;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout << fixed << setprecision(10);
long long int t = 1;
while (t--) {
cin >> n;
if (n.size() % 2) {
long long int x = n.size() + 1;
for (long long int i = 0; i < x / 2; i++) cout << '4';
for (long long int i = 0; i < x / 2; i++) cout << '7';
return 0;
}
long long int x = n.size();
if (check(0, x / 2, x / 2))
cout << n;
else {
cout << '4';
for (long long int i = 0; i < x / 2; i++) cout << '4';
for (long long int i = 0; i < x / 2; i++) cout << '7';
cout << '7';
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
queue<pair<long long, long long> > q;
long long x;
cin >> x;
q.push(make_pair(0, 0));
while (!q.empty()) {
long long val, c;
val = q.front().first;
c = q.front().second;
q.pop();
if ((val >= x) && (c == 0)) {
cout << val;
return 0;
}
q.push(make_pair(val * 10 + 4, c + 1));
q.push(make_pair(val * 10 + 7, c - 1));
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string vow = "aeiou";
const int dxhorse[] = {-2, -2, -1, -1, 1, 1, 2, 2};
const int dyhorse[] = {1, -1, 2, -2, 2, -2, 1, -1};
const int dx[] = {-1, 0, 0, 1};
const int dy[] = {0, -1, 1, 0};
const long double pie = 3.14159265358979;
const long long mod = 1e9 + 7;
long long ans = LLONG_MAX;
long long in;
void f(long long n, int four, int sev) {
if (n > 1e11) return;
if (n >= in) {
if (four == sev) ans = min(ans, n);
}
f(n * 10 + 4, four + 1, sev);
f(n * 10 + 7, four, sev + 1);
}
void solve(int test_case) {
cin >> in;
f(0, 0, 0);
cout << ans;
}
int main() {
int t = 1;
for (int i = 0; i < t; i++) solve(i);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
vector<unsigned long long> v;
char x2[] = "47";
do {
v.push_back(stoi(x2));
} while (next_permutation(x2, x2 + 2));
char x4[] = "4477";
do {
v.push_back(stoi(x4));
} while (next_permutation(x4, x4 + 4));
char x6[] = "444777";
do {
v.push_back(stoi(x6));
} while (next_permutation(x6, x6 + 6));
char x8[] = "44447777";
do {
v.push_back(stoi(x8));
} while (next_permutation(x8, x8 + 8));
v.push_back(4444477777);
sort(v.begin(), v.end());
string s;
cin >> s;
unsigned long long q = stoi(s);
if (q <= v[0]) {
cout << v[0];
return 0;
} else
for (int i = 0; i < v.size() - 1; i++)
if (q == v[i + 1] || (q > v[i] && q < v[i + 1])) {
cout << v[i + 1];
return 0;
}
cout << v[98];
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int oo = 1e9;
const long long mod = 1e7;
int main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
long long n, i = 0ll, d = 0ll, c, f, s;
cin >> n;
while (1) {
c = f = s = 0;
for (int j = 0ll, t = 1ll; j < d; ++j, t *= 10ll)
if (i & (1ll << j))
c += 7ll * t, s++;
else
c += 4ll * t, f++;
if (c >= n && s == f) {
cout << c;
return 0;
}
i++;
if (!((i + 1ll) & (i))) d++;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string get(int n, int m) {
string str;
for (int i = 1; i <= n; i++) str.push_back('4');
for (int i = 1; i <= m; i++) str.push_back('7');
return str;
}
int32_t main() {
ios_base ::sync_with_stdio(0);
cin.tie(0);
string str;
cin >> str;
int n = str.size();
if (n & 1) {
cout << get((n + 1) / 2, (n + 1) / 2) << endl;
return 0;
}
int cnta = 0, cntb = 0, ans = -1, aa = 0, bb = 0;
for (int i = 0; i < n; i++) {
if (cnta + 1 <= n / 2 && str[i] < '7') {
ans = i;
aa = cnta;
bb = cntb;
}
if (cntb + 1 <= n / 2 && str[i] < '4') {
ans = i;
aa = cnta;
bb = cntb;
}
cnta += str[i] == '7';
cntb += str[i] == '4';
if ((str[i] != '4' && str[i] != '7') || cnta > n / 2 || cntb > n / 2) break;
}
if (cnta + cntb == n && cnta == cntb) {
cout << str << endl;
return 0;
}
if (ans == -1) {
cout << get((n + 2) / 2, (n + 2) / 2) << endl;
return 0;
}
string x;
for (int i = 0; i < ans; i++) {
x.push_back(str[i]);
}
if (bb + 1 <= n / 2 && str[ans] < '4') {
++bb;
x.push_back('4');
} else {
++aa;
x.push_back('7');
}
x += get(n / 2 - bb, n / 2 - aa);
cout << x << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
string s, pre, nxt;
int n;
int isLucky() {
for (int i = 0; i < (n); ++i)
if (s[i] != '4' && s[i] != '7') return i;
return n;
}
int main() {
cin >> s;
n = (int)(s).size();
int last = isLucky();
nxt = string(n / 2 + 1, '4') + string(n / 2 + 1, '7');
if (n % 2 == 1) {
cout << nxt << endl;
return 0;
}
pre = s.substr(0, last);
int n4 = count((pre).begin(), (pre).end(), '4'), n7 = last - n4;
if (last == n && n4 == n7) {
cout << s << endl;
return 0;
}
if (last < n && s[last] < '4' && n4 < n / 2 && n7 <= n / 2) {
for (int i = 0; i < (n / 2 - n4); ++i) s[last + i] = '4';
for (int i = 0; i < (n / 2 - n7); ++i) s[last + (n / 2 - n4) + i] = '7';
cout << s << endl;
return 0;
}
if (last < n && s[last] < '7' && n7 < n / 2 && n4 <= n / 2) {
s[last] = '7';
n7++;
for (int i = 0; i < (n / 2 - n4); ++i) s[last + 1 + i] = '4';
for (int i = 0; i < (n / 2 - n7); ++i) s[last + 1 + (n / 2 - n4) + i] = '7';
cout << s << endl;
return 0;
}
for (int i = (last - 1); i >= (0); --i)
if (s[i] == '4' && n7 < n / 2 && n4 <= n / 2 + 1) {
s[i] = '7';
n7++;
n4--;
for (int j = 0; j < (n / 2 - n4); ++j) s[i + 1 + j] = '4';
for (int j = 0; j < (n / 2 - n7); ++j) s[i + 1 + (n / 2 - n4) + j] = '7';
cout << s << endl;
return 0;
} else if (s[i] == '4')
n4--;
else
n7--;
cout << nxt << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s, t, ans;
void f(int i, int x, int y, bool flag) {
if (x > s.size() / 2 || y > s.size() / 2) return;
if (i == s.size()) {
ans = t;
return;
}
if (flag) {
t[i] = '4';
f(i + 1, x + 1, y, 1);
if (ans != "") return;
t[i] = '7';
f(i + 1, x, y + 1, 1);
} else {
if ('4' >= s[i]) {
t[i] = '4';
f(i + 1, x + 1, y, '4' > s[i]);
if (ans != "") return;
}
if ('7' >= s[i]) {
t[i] = '7';
f(i + 1, x, y + 1, '7' > s[i]);
}
}
}
int main() {
cin >> s;
for (int i = 1; i <= s.size() / 2; ++i) t += '7';
for (int i = 1; i <= s.size() / 2; ++i) t += '4';
if (s > t || s.size() % 2) {
t = "";
for (int i = 1; i <= s.size() / 2 + 1; ++i) t += '4';
for (int i = 1; i <= s.size() / 2 + 1; ++i) t += '7';
cout << t << endl;
return 0;
}
t = s;
f(0, 0, 0, 0);
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
int lln(const char *line, char *output, int fours, int sevens) {
int i, digit;
if (*line == '\0') {
*output = '\0';
return ((fours + sevens) != 0);
}
digit = *line - '0';
if (digit < 4 && fours) {
*output = '4';
fours--;
output++;
} else if (digit == 4 && fours) {
*output = '4';
if (lln(line + 1, output + 1, fours - 1, sevens)) {
if (sevens) {
*output = '7';
sevens--;
} else {
return 1;
}
} else {
return 0;
}
output++;
} else if (digit < 7 && sevens) {
*output = '7';
sevens--;
output++;
} else if (digit == 7 && sevens) {
*output = '7';
if (lln(line + 1, output + 1, fours, sevens - 1)) {
return 1;
} else {
return 0;
}
} else {
return 1;
}
for (i = 0; i < fours; i++) {
*output = '4';
output++;
}
for (i = 0; i < sevens; i++) {
*output = '7';
output++;
}
*output = '\0';
return 0;
}
int main(int argc, char *argv[]) {
char line[100000 + 3], result[100000 + 3];
int i, len;
gets(line);
len = strlen(line);
if ((len & 1) || (line[0] > '7')) {
len = (len & 1 ? (len + 1) / 2 : len / 2 + 1);
for (i = 0; i < len; i++) {
printf("4");
}
for (i = 0; i < len; i++) {
printf("7");
}
printf("\n");
} else {
if (lln(line, result, len / 2, len / 2)) {
len = len / 2 + 1;
for (i = 0; i < len; i++) {
printf("4");
}
for (i = 0; i < len; i++) {
printf("7");
}
printf("\n");
} else {
printf("%s\n", result);
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char str[100005];
int flag[100005];
void print(int len) {
for (int i = 0; i < len / 2; i++) {
printf("4");
}
for (int j = len / 2; j < len; j++) {
printf("7");
}
printf("\n");
}
int main() {
scanf("%s", str);
int len = strlen(str);
memset(flag, 0, sizeof(flag));
if (len % 2) {
print(len + 1);
} else {
if ((str[0] - '0') > 7) {
print(len + 2);
} else {
int cnt = 0, x = 0, y = 0;
for (int i = len - 1; i >= 0; i--) {
if ((str[i] - '0' + cnt) > 7) {
if (i == 0) {
print(len + 2);
return 0;
}
cnt = 1;
str[i] = '4';
} else if ((str[i] - '0' + cnt) > 4 && (str[i] - '0' + cnt) < 7) {
cnt = 0;
str[i] = '7';
flag[i + 1] = 1;
} else if ((str[i] - '0' + cnt) < 4) {
cnt = 0;
str[i] = '4';
flag[i + 1] = 1;
} else if ((str[i] - '0' + cnt) == 4) {
str[i] = '4';
if (cnt) {
flag[i + 1] = 1;
}
cnt = 0;
} else {
str[i] = '7';
if (cnt) {
flag[i + 1] = 1;
}
cnt = 0;
}
}
int pos = -1;
for (int i = 0; i < len; i++) {
if (flag[i]) {
pos = i;
break;
}
}
if (pos != -1)
for (int i = pos; i < len; i++) {
str[i] = '4';
}
for (int i = 0; i < len; i++) {
if (str[i] == '4')
x++;
else
y++;
}
if (x == y)
printf("%s\n", str);
else if (x > y) {
int ans = x - y, flag = 0;
for (int i = len - 1; i >= 0; i--) {
if (ans == 0) {
printf("%s\n", str);
break;
} else {
if (str[i] == '4') {
str[i] = '7';
ans -= 2;
}
}
}
} else {
int ans = y - x;
for (int i = len - 1; i >= 0; i--) {
int p = 0;
if ((str[i] - '0') == 4) {
for (int j = 0; j < i; j++) {
if (str[j] == '4') p++;
}
if (((len - 1 - i) + p) >= len / 2) {
str[i] = '7';
ans += 2;
for (int j = i + 1; j < len; j++) {
if (ans == 0) {
printf("%s\n", str);
return 0;
}
if (str[j] == '7') {
str[j] = '4';
ans -= 2;
}
}
printf("%s\n", str);
return 0;
}
}
}
print(len + 2);
}
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
char ans[100005];
string st;
int n;
int main() {
ios::sync_with_stdio(false);
while (cin >> st) {
n = st.size();
string tmps = "";
for (int i = 0; i < n / 2; i++) {
tmps += '7';
}
for (int i = 0; i < n / 2; i++) {
tmps += '4';
}
if (n % 2 == 1 || st > tmps) {
for (int i = 0; i < n / 2 + 1; i++) {
cout << '4';
}
for (int i = 0; i < n / 2 + 1; i++) {
cout << '7';
}
cout << endl;
} else {
int num4 = n / 2, num7 = n / 2;
bool flag = false;
string ans = "";
for (int i = 0; i < n; i++) {
bool four = false;
if (num4 > 0) {
if (st[i] < '4' || flag) {
four = true;
} else if (st[i] == '4') {
for (int j = i + 1; j <= n; j++) {
if (j == n) {
four = true;
break;
}
char c = j - i;
if (c <= num7) {
c = '7';
} else {
c = '4';
}
if (c > st[j]) {
four = true;
}
if (c != st[j]) {
break;
}
}
}
}
if (four) {
ans += '4';
num4--;
} else {
ans += '7';
num7--;
}
if (ans[i] > st[i]) {
flag = true;
}
}
cout << ans << endl;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const long long N = 1e3 + 5;
vector<long long> v;
void lucky(long long n) {
if (n > 1e8) {
return;
}
v.push_back(10 * n + 4);
v.push_back(10 * n + 7);
lucky(10 * n + 4);
lucky(10 * n + 7);
}
long long SL(long long n) {
string s = to_string(n);
long long m = (long long)((s).size());
if (m % 2) return -1;
sort((s).begin(), (s).end());
m /= 2;
if (s[m] == '7' && s[m - 1] == '4') {
return 1;
}
return -1;
}
void solve() {
lucky(0);
v.push_back(4444477777);
sort((v).begin(), (v).end());
long long n;
cin >> n;
for (long long i = 0; i < (long long)((v).size()); i++) {
if (v[i] >= n && SL(v[i]) == 1) {
cout << v[i] << ' ';
return;
}
}
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
long long t = 1;
while (t--) solve();
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
struct print {
template <typename T>
print& operator,(const T& v) {
std::cout << v << " ";
return *this;
}
};
int main() {
long long a[] = {47, 74, 4477, 4747, 4774, 7447, 7474, 7744};
vector<long long> v(a, a + 8);
long long n;
scanf("%lld", &n);
string str = "4444477777";
long long t = 0;
do {
t = 0;
for (int i = 0; i < str.size(); i++) {
t *= 10;
t += str[i] - '0';
}
v.push_back(t);
} while (next_permutation(str.begin(), str.end()));
str = "44447777";
t = 0;
do {
t = 0;
for (int i = 0; i < str.size(); i++) {
t *= 10;
t += str[i] - '0';
}
v.push_back(t);
} while (next_permutation(str.begin(), str.end()));
str = "444777";
t = 0;
do {
t = 0;
for (int i = 0; i < str.size(); i++) {
t *= 10;
t += str[i] - '0';
}
v.push_back(t);
} while (next_permutation(str.begin(), str.end()));
sort(v.begin(), v.end());
for (int i = 0; i < v.size(); i++) {
if (v[i] >= n) {
print(), v[i], "\n";
return 0;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long INF = 1e9 + 9;
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cout.precision(10);
cout << fixed;
long long n;
cin >> n;
long long d = floor(log10(n) + 1);
vector<long long> v;
for (long long i = 2; i <= 12; i += 2) {
for (long long j = 0; j < (1LL << i); j++) {
string str;
if (__builtin_popcount(j) == i / 2) {
for (long long z = i - 1; z >= 0; z--) {
if (j & (1LL << z)) {
str.push_back('7');
} else
str.push_back('4');
}
v.push_back(stoll(str));
}
}
}
if (d & 1) {
for (long long i = 1; i <= (d + 1) / 2; i++) cout << 4;
for (long long i = 1; i <= (d + 1) / 2; i++) cout << 7;
} else {
cout << *lower_bound((v).begin(), (v).end(), n);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 100005;
int len;
char s[N], ans[N];
void print(int k) {
for (int i = 1; i <= k / 2; i++) cout << '4';
for (int i = 1; i <= k / 2; i++) cout << '7';
}
bool search(int k, int c4, int c7, int f) {
if (k == len) return 1;
if (f) {
for (int i = 0; i + k < len; i++) {
if (i < len / 2 - c4)
ans[i + k] = '4';
else
ans[i + k] = '7';
}
return 1;
}
if (c4 < len / 2 && s[k] <= '4') {
if (search(k + 1, c4 + 1, c7, s[k] < '4')) {
ans[k] = '4';
return 1;
}
}
if (c7 < len / 2 && s[k] <= '7') {
if (search(k + 1, c4, c7 + 1, s[k] < '7')) {
ans[k] = '7';
return 1;
}
}
return 0;
}
int main() {
scanf("%s", s);
len = strlen(s);
if (len & 1)
print(len + 1);
else {
if (search(0, 0, 0, 0))
printf("%s", ans);
else
print(len + 2);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
static const double EPS = 1e-9;
string make_least_47(int n) {
string ret;
for (int i = 0; i < (int)(n); i++) {
ret += '4';
}
for (int i = 0; i < (int)(n); i++) {
ret += '7';
}
return ret;
}
string make_least_47_2(int r4, int r7) {
string ret;
for (int i = 0; i < (int)(r4); i++) {
ret += '4';
}
for (int i = 0; i < (int)(r7); i++) {
ret += '7';
}
return ret;
}
int main(void) {
string ns;
cin >> ns;
int N = ns.length();
string ret;
if (N & 1) {
ret = make_least_47((N + 1) / 2);
cout << ret << endl;
return 0;
}
int c4 = 0;
int c7 = 0;
int last4 = -1;
int last7 = -1;
for (int i = 0; i < (int)(N); i++) {
if (ns[i] == '4') {
if (c4 == N / 2) {
ret += make_least_47_2(N / 2 - c4, N / 2 - c7);
break;
}
c4++;
last4 = i;
ret += ns[i];
} else if (ns[i] == '7') {
if (c7 == N / 2) {
if (c4 == 0) {
ret = make_least_47((N + 2) / 2);
} else {
c4 = c7 = 0;
ret = "";
if (last4 > last7) {
last4 = last7;
while (ns[last4] == '7') last4--;
}
for (int j = 0; j < (int)(last4); j++) {
if (ns[j] == '4')
c4++;
else
c7++;
ret += ns[j];
}
ret += '7';
c7++;
ret += make_least_47_2(N / 2 - c4, N / 2 - c7);
}
break;
}
c7++;
last7 = i;
ret += ns[i];
} else {
if (ns[i] > '7') {
if (c4 == 0 || (c7 == (N / 2) && last7 == (N / 2 - 1))) {
ret = make_least_47((N + 2) / 2);
} else {
c4 = c7 = 0;
ret = "";
if (c7 == N / 2 && last4 > last7) {
last4 = last7;
while (ns[last4] == '7') last4--;
}
for (int j = 0; j < (int)(last4); j++) {
if (ns[j] == '4')
c4++;
else
c7++;
ret += ns[j];
}
ret += '7';
c7++;
ret += make_least_47_2(N / 2 - c4, N / 2 - c7);
}
} else if (ns[i] < '4') {
ret += make_least_47_2(N / 2 - c4, N / 2 - c7);
} else {
if (last7 == (N / 2 - 1)) {
ret = make_least_47((N + 2) / 2);
} else if (c7 == N / 2) {
c4 = c7 = 0;
ret = "";
if (last4 > last7) {
last4 = last7;
while (ns[last4] == '7') last4--;
}
for (int j = 0; j < (int)(last4); j++) {
if (ns[j] == '4')
c4++;
else
c7++;
ret += ns[j];
}
ret += '7';
c7++;
ret += make_least_47_2(N / 2 - c4, N / 2 - c7);
} else {
ret += '7';
c7++;
ret += make_least_47_2(N / 2 - c4, N / 2 - c7);
}
}
break;
}
}
cout << ret << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 111111;
char s[MAXN];
int a[MAXN];
int o[MAXN], z[MAXN];
int l[MAXN];
int n;
int main() {
gets(s);
n = strlen(s);
reverse(s, s + n);
for (int i = 0; i < n; i++) a[i] = s[i] - '0';
for (int i = n - 1; i >= 0; i--) {
if (a[i] == 4 || a[i] == 7) {
a[i] = a[i] == 4 ? 0 : 1;
continue;
}
int d = 7 < a[i];
a[i] = a[i] <= 4 || 7 < a[i] ? 0 : 1;
for (int j = i + 1; j < n; j++) {
d += a[j];
a[j] = d & 1;
d >>= 1;
}
if (d) n++;
for (int j = i - 1; j >= 0; j--) a[j] = 0;
break;
}
if (n & 1) {
n++;
for (int i = 0; i < n; i++) printf("%d", (i >= n / 2) * 3 + 4);
printf("\n");
return 0;
}
for (int i = n - 1; i >= 0; i--) {
l[i] = (l[i + 1] + 1) * a[i];
z[i] = z[i + 1] + (a[i] == 0);
o[i] = o[i + 1] + (a[i] == 1);
}
if (z[0] == o[0]) {
for (int i = n - 1; i >= 0; i--) printf("%d", a[i] * 3 + 4);
printf("\n");
return 0;
}
for (int i = 0; i < n; i++)
if (z[i] && z[i] - 1 + l[i] + i >= n / 2 && o[i] + 1 - l[i] + i >= n / 2) {
int d = 1;
for (int j = i; j < n; j++) {
d += a[j];
a[j] = d & 1;
d >>= 1;
}
for (int j = 0; j < i; j++) a[j] = j < n / 2 - (o[i] + 1 - l[i]);
for (int i = n - 1; i >= 0; i--) printf("%d", a[i] * 3 + 4);
printf("\n");
return 0;
}
n += 2;
for (int i = 0; i < n; i++) printf("%d", (i >= n / 2) * 3 + 4);
printf("\n");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string n;
int ans[100005];
int l;
int luck(int t) {
if (t == l) {
return 1;
}
if (n[t] < '4') {
ans[t] = 4;
for (int i = t; i < l; i++) {
ans[i] = 4;
}
return 1;
} else if (n[t] == '4') {
if (luck(t + 1)) {
ans[t] = 4;
} else {
ans[t] = 7;
}
return 1;
} else if (n[t] < '7') {
ans[t] = 7;
for (int i = t + 1; i < l; i++) {
ans[i] = 4;
}
return 1;
} else if (n[t] == '7') {
if (luck(t + 1)) {
ans[t] = 7;
return 1;
} else {
ans[t] = 4;
return 0;
}
} else {
ans[t] = 4;
return 0;
}
}
int main() {
cin >> n;
l = n.size();
string m;
for (int i = 0; i < l / 2; i++) {
m.push_back('7');
}
for (int i = 0; i < l / 2; i++) {
m.push_back('4');
}
if (l % 2 || n > m) {
for (int i = 0; i <= l / 2; i++) {
printf("4");
}
for (int i = 0; i <= l / 2; i++) {
printf("7");
}
} else {
int f = 0;
for (int i = 0; i < l; i++) {
if (ans[i]) {
continue;
}
luck(i);
}
for (int i = 0; i < l; i++) {
if (ans[i] == 4) {
f++;
}
}
f -= l / 2;
if (f > 0) {
for (int i = l - 1; i >= 0; i--) {
if (ans[i] == 4) {
ans[i] = 7;
f--;
}
if (f == 0) {
break;
}
}
} else if (f < 0) {
bool flag = 1;
int s = 0;
for (int i = l - 1; i >= 0; i--) {
if (ans[i] == 7) {
s++;
} else {
if (s + f >= 1) {
ans[i] = 7;
for (int j = i + 1; j < l; j++) {
if (ans[j] == 7) {
ans[j] = 4;
f++;
}
if (f == 1) {
break;
}
}
flag = 0;
break;
}
}
}
if (flag) {
for (int i = 0; i <= l / 2; i++) {
printf("4");
}
for (int i = 0; i <= l / 2; i++) {
printf("7");
}
return 0;
}
}
for (int i = 0; i < l; i++) {
printf("%d", ans[i]);
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long double PI = 3.141592653589793238462643383279502884197;
priority_queue<int, vector<int>, greater<int> > pq;
vector<int> v;
char s[100003];
int n;
void pr(int len) {
for (int i = 0; i < len / 2; i++) printf("4");
for (int i = 0; i < len / 2; i++) printf("7");
return;
}
void go(int o) {
if (o == n) return;
int j;
if (s[o] == 4 || s[o] == 7)
go(o + 1);
else {
if (s[o] > 7) {
for (j = o - 1; j >= 0; j--)
if (s[j] == 4) break;
if (j == -1) {
if (n % 2)
pr(n + 1);
else
pr(n + 2);
exit(0);
} else {
s[j] = 7;
for (int i = j + 1; i < n; i++) s[i] = 4;
}
} else if (s[o] > 4) {
s[o] = 7;
for (int i = o + 1; i < n; i++) s[i] = 4;
} else {
for (int i = o; i < n; i++) s[i] = 4;
}
}
}
int main() {
scanf("%s", s);
n = strlen(s);
if (n % 2) {
pr(n + 1);
return 0;
}
for (int i = 0; i < n; i++) s[i] -= '0';
go(0);
int ff = 0, ss = 0;
for (int i = 0; i < n; i++) {
if (s[i] == 4)
ff++;
else
ss++;
}
if (ff == ss) {
for (int i = 0; i < n; i++) printf("%d", s[i]);
return 0;
}
int l = n - 1;
while (l >= 0 && !(ss <= n / 2 - 1 && ff <= n / 2 + 1 && s[l] == 4)) {
if (s[l] == 4)
ff--;
else
ss--;
l--;
}
if (l == -1) {
pr(n + 2);
return 0;
} else {
s[l++] = 7;
ss++;
ff--;
while (ff < n / 2) {
ff++;
s[l++] = 4;
}
while (l < n) s[l++] = 7;
}
for (int i = 0; i < n; i++) printf("%d", s[i]);
}
|
#include <bits/stdc++.h>
int N, four[100005], svn[100005];
char buf[100005];
int main() {
int i, j, k, a = 0, b = 0;
scanf("%s", buf), N = strlen(buf);
if (N & 1) {
for (i = N; i; i--) buf[i] = buf[i - 1];
buf[0] = '0';
buf[++N] = 0;
}
for (i = 0; i < N; i++) {
four[i] = a, svn[i] = b;
if (buf[i] == '4')
a++;
else if (buf[i] == '7')
b++;
}
if (a + b == N && a == b) {
puts(buf);
return 0;
}
for (i = N; i--;) {
a = four[i], b = svn[i];
if (a + b != i || a > N / 2 || b > N / 2) continue;
k = 0;
if (buf[i] < '4' && a < N / 2)
k = 4;
else if (buf[i] < '7' && b < N / 2)
k = 7;
if (!k) continue;
for (j = 0; j < i; j++) printf("%c", buf[j]);
printf("%c", '0' + k);
if (k == 4)
a++;
else
b++;
for (j = i + 1; j < N; j++) {
if (a < N / 2)
a++, printf("4");
else
b++, printf("7");
}
return 0;
}
for (i = 0; i < N / 2 + 1; i++) printf("4");
for (i = 0; i < N / 2 + 1; i++) printf("7");
}
|
#include <bits/stdc++.h>
using namespace std;
string st;
long n, s[200000][3], ap, av;
bool nice(string st) {
long s1, s2;
s1 = s2 = 0;
for (int i = 0; i < st.size(); i++)
if (st[i] == '4')
++s1;
else if (st[i] == '7')
++s2;
if (s1 == s2 && s1 + s2 == st.size()) return true;
return false;
}
int main() {
ios_base::sync_with_stdio(0);
cin >> st;
if (nice(st))
cout << st << endl;
else if (st.size() % 2) {
n = st.size() + 1;
n /= 2;
for (int i = 0; i < n; i++) cout << 4;
for (int i = 0; i < n; i++) cout << 7;
cout << endl;
} else {
ap = av = -1;
for (int i = 1; i <= st.size(); i++) {
s[i][0] = s[i - 1][0];
s[i][1] = s[i - 1][1];
if (st[i - 1] == '4') s[i][0]++;
if (st[i - 1] == '7') s[i][1]++;
}
for (int i = st.size() - 1; i >= 0; --i) {
if (s[i][0] + s[i][1] != i) continue;
if (st[i] < '4' && abs(s[i][0] + 1 - s[i][1]) < st.size() - i) {
ap = i;
av = 4;
break;
}
if (st[i] < '7' && abs(s[i][0] - s[i][1] - 1) < st.size() - i) {
ap = i;
av = 7;
break;
}
}
if (ap == -1) {
n = st.size() / 2;
for (int i = 0; i <= n; i++) cout << 4;
for (int i = 0; i <= n; i++) cout << 7;
cout << endl;
} else {
long need4 = st.size() / 2;
for (int i = 0; i < ap; i++) {
cout << st[i];
if (st[i] == '4') --need4;
}
cout << av;
if (av == 4) --need4;
for (int i = ap + 1; i < st.size(); i++) {
if (need4) {
cout << 4;
--need4;
} else
cout << 7;
}
cout << endl;
}
}
cin.get();
cin.get();
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
vector<char> s, ans;
ostream& operator<<(ostream& out, vector<char>& t) {
for (int i = 0; i < t.size(); i++) printf("%c", t[i]);
return out;
}
void genSuff(int ind, int fr, int sv, vector<char>& a) {
while (a.size() > ind) a.pop_back();
for (int i = 0; i < fr; i++) a.push_back('4');
for (int i = 0; i < sv; i++) a.push_back('7');
}
void tryGen(vector<char> s) {
if (s.size() & 1) return;
int mini = -1, kfr, ksv, n = s.size(), fr = n / 2, sv = n / 2;
for (int i = 0; i < n && ans.size() < n; i++)
if (s[i] < '4') {
ans.push_back(fr != 0 ? '4' : '7');
genSuff(i + 1, fr - (fr > 0), sv - (fr == 0), ans);
} else if (s[i] == '4' && fr > 0) {
ans.push_back('4');
fr--;
if (sv != 0) {
mini = i;
kfr = fr;
ksv = sv;
}
} else if (s[i] == '4') {
ans.push_back('7');
genSuff(i + 1, fr, sv - 1, ans);
} else if (s[i] <= '7' && sv > 0) {
ans.push_back('7');
sv--;
if (s[i] < '7') genSuff(i + 1, fr, sv, ans);
} else {
if (mini == -1) {
ans.clear();
return;
}
ans[mini] = '7';
ksv--;
kfr++;
genSuff(mini + 1, kfr, ksv, ans);
}
}
int main() {
char r;
while (cin >> r) s.push_back(r);
tryGen(s);
if (ans.size() == 0) genSuff(0, (s.size() + 2) / 2, (s.size() + 2) / 2, ans);
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char str1[1000000];
char ans[1000000];
int n;
bool chek() {
int c1, c2;
c1 = 0;
c2 = 0;
for (int i = 0; i < n; i++) {
if (str1[i] == '4')
c1++;
else if (str1[i] == '7')
c2++;
else
return false;
}
return (c1 == c2);
}
bool banano(int pos, int c1, int c2, int l) {
if (pos == n) {
if (c1 == c2 && c1 == 0 && l == 1) return true;
return false;
}
if (l == 1) {
int i = pos;
while (c1--) ans[i] = '4', i++;
while (c2--) ans[i] = '7', i++;
ans[i] = 0;
return true;
}
if (str1[pos] < '4') {
if (c1 > 0) {
ans[pos] = '4';
if (banano(pos + 1, c1 - 1, c2, 1)) return true;
return false;
}
if (c2 > 0) {
ans[pos] = '7';
if (banano(pos + 1, c1, c2 - 1, 1)) return true;
return false;
}
} else if (str1[pos] == '4') {
if (c1 > 0) {
ans[pos] = '4';
if (banano(pos + 1, c1 - 1, c2, 0)) return true;
}
if (c2 > 0) {
ans[pos] = '7';
if (banano(pos + 1, c1, c2 - 1, 1)) return true;
return false;
}
} else if (str1[pos] < '7') {
if (c2 > 0) {
ans[pos] = '7';
if (banano(pos + 1, c1, c2 - 1, 1)) return true;
return false;
}
return false;
} else if (str1[pos] == '7') {
if (c2 > 0) {
ans[pos] = '7';
if (banano(pos + 1, c1, c2 - 1, 0)) return true;
return false;
}
}
return false;
}
int main() {
scanf("%s", &str1);
n = strlen(str1);
if (n % 2 == 1) {
for (int i = 1; i <= (n + 1) / 2; i++) printf("4");
for (int i = 1; i <= (n + 1) / 2; i++) printf("7");
printf("\n");
return 0;
}
if (chek()) {
printf("%s\n", str1);
return 0;
}
if (banano(0, n / 2, n / 2, 0)) {
printf("%s\n", ans);
return 0;
}
for (int i = 1; i <= (n / 2) + 1; i++) printf("4");
for (int i = 1; i <= (n / 2) + 1; i++) printf("7");
printf("\n");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
string s;
int n;
cin >> n;
int k = 0;
int h = 0;
if (n > 77774444) {
cout << 4444477777;
return 0;
}
for (int i = n; i <= 1000000000; i++) {
int j = i;
h = 0;
k = 0;
while (j > 0) {
if (j % 10 != 4 && j % 10 != 7) {
h = -1;
k = 0;
break;
}
if (j % 10 == 4) {
k++;
} else {
h++;
}
j = j / 10;
}
if (h == k) {
cout << i << endl;
break;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
string n;
cin >> n;
int l = n.length();
vector<long long> superl;
for (int len = l; len <= 10; len++) {
if (len % 2) continue;
for (int mask = 0; mask < 1 << len; mask++) {
if (__builtin_popcount(mask) != len / 2) continue;
string lucky;
for (int i = 0; i < len; i++) {
if (mask & (1 << i))
lucky.push_back('7');
else
lucky.push_back('4');
}
long long luckyn;
stringstream(lucky) >> luckyn;
superl.push_back(luckyn);
}
}
sort(superl.begin(), superl.end());
int nn;
stringstream(n) >> nn;
cout << *lower_bound(superl.begin(), superl.end(), nn);
}
|
#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000100;
const int MAXN = 1000100;
string s;
int gr[] = {0, 4, 5, 7, 8, 10};
int last[10], n;
int ost[MAXN][5];
int czy_mniejsze_od_7(int p, int k) {
int mini = INF;
for (int i = 0; i < 3; i++) {
mini = min(mini, ost[p][i]);
}
if (mini > k && ost[p][4] > k) {
return 0;
}
if (mini > ost[p][4]) {
return -1;
}
return 1;
}
int czy_mniejsze_od_4(int p, int k) {
int mini = INF;
for (int i = 2; i < 5; i++) {
mini = min(mini, ost[p][i]);
}
if (mini > k && ost[p][0] > k) {
return 0;
}
if (mini < ost[p][0]) {
return -1;
}
return 1;
}
bool da_sie(int suf, int pula4, int pula7) {
int ost7 = suf + pula7 - 1;
int x = czy_mniejsze_od_7(suf, ost7);
if (x == -1) {
return false;
}
if (x == 1) {
return true;
}
x = czy_mniejsze_od_4(ost7 + 1, n - 1);
if (x == -1) {
return false;
}
return true;
}
int main() {
ios_base::sync_with_stdio(false);
cin >> s;
n = s.size();
if (n % 2 == 1) {
n++;
res:
for (int i = 0; i < n / 2; i++) {
cout << 4;
}
for (int i = 0; i < n / 2; i++) {
cout << 7;
}
cout << endl;
return 0;
}
for (int i = 0; i < 10; i++) {
last[i] = INF;
}
for (int i = n - 1; i >= 0; i--) {
last[s[i] - '0'] = i;
ost[i][0] = ost[i][1] = ost[i][2] = ost[i][3] = ost[i][4] = INF;
for (int j = 0; j < 5; j++) {
ost[i][j] = INF;
for (int k = gr[j]; k < gr[j + 1]; k++) {
ost[i][j] = min(ost[i][j], last[k]);
}
}
}
int ok = 0;
for (int i = 0; i < n / 2; i++) {
if (s[i] < '7') {
ok = 1;
break;
} else if (s[i] > '7') {
ok = -1;
break;
}
}
if (ok == -1) {
n += 2;
goto res;
}
if (ok == 0) {
for (int i = n / 2; i < n; i++) {
if (s[i] < '4') {
ok = 1;
break;
} else if (s[i] > '4') {
ok = -1;
break;
}
}
if (ok == -1) {
n += 2;
goto res;
}
}
bool row = true;
int pula4 = n / 2, pula7 = n / 2;
for (int i = 0; i < s.size(); i++) {
if (pula4 == 0) {
cout << 7;
pula7--;
} else if (pula7 == 0) {
cout << 4;
pula4--;
} else {
int x = da_sie(i + 1, pula4 - 1, pula7);
int wyp;
if (row && s[i] < '4') {
cout << 4;
pula4--;
row = false;
} else if (row && s[i] > '4') {
if (s[i] != '7') {
row = false;
}
cout << 7;
pula7--;
} else if (x || !row) {
cout << 4;
if (4 != s[i] - '0') {
row = false;
}
pula4--;
} else {
cout << 7;
if (s[i] - '0' != 7) {
row = false;
}
pula7--;
}
}
}
cout << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100010;
const int MAXM = 300010;
const int INF = 0x7fffffff;
const int MOD = 1e9 + 7;
const double eps = 1e-6;
const long double pi = acos(-1.0);
char ans[100010], st[100010];
void fuck(int i, int j) {
while (ans[j]) {
swap(ans[j], ans[i]);
i++;
j++;
}
}
int main() {
scanf("%s", st);
int n = strlen(st);
if (n & 1 == 1) {
for (int i = 0; i < n / 2 + 1; ++i) {
printf("4");
}
for (int i = 0; i < n / 2 + 1; ++i) {
printf("7");
}
printf("\n");
return 0;
}
int m = n / 2;
for (int i = 0; i < m; ++i) {
ans[i] = '7';
}
for (int i = 0; i < m; ++i) {
ans[m + i] = '4';
}
bool t = 0;
for (int i = 0; i < n; ++i) {
if (ans[i] > st[i]) break;
if (ans[i] < st[i]) {
t = 1;
break;
}
}
if (t) {
for (int j = 0; j < n / 2 + 1; ++j) {
printf("4");
}
for (int j = 0; j < n / 2 + 1; ++j) {
printf("7");
}
printf("\n");
return 0;
}
int nxt = 0;
for (int i = 0; i < n; ++i) {
if (ans[i] > st[i]) {
nxt = i;
break;
}
}
ans[n] = 0;
st[n] = -1;
while (nxt < n) {
for (int i = nxt; i <= n; ++i) {
if (ans[i] > st[i]) {
nxt = i;
break;
}
}
if (nxt == n || ans[nxt] == '4') break;
if (st[nxt] < '4') {
fuck(nxt, m);
break;
}
if (st[nxt] == '4') {
swap(ans[nxt], ans[m]);
int i;
for (i = nxt; i <= n; ++i) {
if (ans[i] != st[i]) break;
}
if (ans[i] > st[i]) {
m++;
nxt = i;
continue;
}
swap(ans[nxt], ans[m]);
fuck(nxt + 1, m);
break;
}
if (st[nxt] < '7') {
fuck(nxt + 1, m);
break;
}
}
printf("%s\n", ans);
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin >> n;
if (n > 77774444) {
cout << "4444477777";
return 0;
}
for (int i = n;; i++) {
int flag4 = 0;
int flag7 = 0;
int flag = 1;
int x = i;
while (x > 0) {
if (x % 10 == 4) {
flag4++;
} else if (x % 10 == 7) {
flag7++;
} else {
flag = 0;
}
x /= 10;
}
if (flag == 0) continue;
if (flag4 == flag7) {
cout << i;
return 0;
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
int len;
string s;
char ans[100005];
bool dfs(int pos, int cnt4, int cnt7, bool flag) {
if (pos == len) return true;
if (flag) {
for (int i = 0; i < cnt4; i++) ans[pos++] = '4';
for (int i = 0; i < cnt7; i++) ans[pos++] = '7';
return true;
}
if (s[pos] <= '4' && cnt4) {
if (dfs(pos + 1, cnt4 - 1, cnt7, s[pos] < '4')) {
ans[pos] = '4';
return true;
}
}
if (s[pos] <= '7' && cnt7) {
if (dfs(pos + 1, cnt4, cnt7 - 1, s[pos] < '7')) {
ans[pos] = '7';
return true;
}
}
return false;
}
int main() {
cin >> s;
len = s.length();
if (len % 2 || !dfs(0, len / 2, len / 2, false)) {
len = len % 2 ? (len + 1) / 2 : (len + 2) / 2;
for (int i = 0; i < len; i++) cout << 4;
for (int i = 0; i < len; i++) cout << 7;
cout << endl;
}
cout << ans << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
string s;
int n;
void printMin(int sz) {
for (int i = 0; i < sz / 2; i++) {
cout << 4;
}
for (int i = sz / 2; i < sz; i++) {
cout << 7;
}
cout << endl;
}
inline bool ok() {
for (int i = 0; i < n / 2; i++) {
if (s[i] == '4') return true;
}
return false;
}
inline void balance(int bal) {
if (!ok()) {
printMin(n + 2);
return;
}
int mark = 0;
int fours = 0;
for (int i = n - 1; i >= 0; i--) {
fours++;
if (s[i] == '7') {
s[i] = '4';
bal -= 2;
mark = i;
}
if (bal == -2) break;
}
if (bal != -2) {
printMin(n + 2);
return;
}
int i = mark - 1;
for (; i >= 0; i--) {
if (s[i] == '4') {
s[i] = '7';
bal += 2;
break;
}
}
i++;
for (int count = 0; count < fours; count++) {
s[i] = '4';
i++;
}
for (; i < n; i++) {
s[i] = '7';
}
if (bal == 0) {
cout << s << endl;
} else {
printMin(n + 2);
}
}
int main(void) {
cin >> s;
n = s.size();
if (n % 2 == 1) {
printMin(n + 1);
return 0;
}
int bal = 0, idx = 0, mark;
bool flag = false;
for (; idx < n; idx++) {
if (s[idx] == '4') {
continue;
} else if (s[idx] == '7') {
continue;
} else if (s[idx] < '4') {
s[idx] = '4';
mark = idx + 1;
break;
} else if (s[idx] < '7') {
s[idx] = '7';
mark = idx + 1;
break;
} else {
flag = true;
mark = idx - 1;
idx--;
break;
}
}
if (flag) {
for (; mark >= 0; mark--) {
if (s[mark] == '4') {
s[mark] = '7';
flag = false;
mark++;
break;
}
}
}
if (flag) {
printMin(n + 2);
return 0;
}
for (; mark < n; mark++) {
s[mark] = '4';
}
bal = 0;
for (int index = 0; index < n; index++) {
if (s[index] == '4') {
bal--;
} else if (s[index] == '7') {
bal++;
}
}
if (bal == 0) {
cout << s << endl;
return 0;
} else if (bal < 0) {
for (int i = n - 1; i >= 0; i--) {
if (s[i] == '4') {
s[i] = '7';
bal += 2;
}
if (bal == 0) break;
}
cout << s << endl;
} else {
balance(bal);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s, ans;
int n;
bool Try(int j, int n4, int n7, bool flag) {
if (j == n) return true;
if (flag) {
for (int i = 0; i < n4; i++) ans[i + j] = '4';
j += n4;
for (int i = 0; i < n7; i++) ans[i + j] = '7';
return true;
}
if (n4 > 0 && s[j] <= '4') {
if (Try(j + 1, n4 - 1, n7, s[j] < '4')) {
ans[j] = '4';
return true;
}
}
if (n7 > 0 && s[j] <= '7') {
if (Try(j + 1, n4, n7 - 1, s[j] < '7')) {
ans[j] = '7';
return true;
}
}
return false;
}
int main() {
cin >> s;
n = (int)s.size();
ans.resize(n);
if (n & 1 || !Try(0, n / 2, n / 2, false)) {
n += 2;
for (int i = 1; i <= n / 2; i++) cout << 4;
for (int i = 1; i <= n / 2; i++) cout << 7;
} else
cout << ans;
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100005];
int n;
int main() {
while (~scanf("%s", s)) {
n = strlen(s);
if (n & 1) {
n = (n + 1) / 2;
for (int i = 0; i < n; i++) putchar('4');
for (int i = 0; i < n; i++) putchar('7');
puts("");
continue;
}
int c4 = 0, c7 = 0, big = 0, can = 1;
for (int i = 0; i < n; i++) {
if (big) {
while (i < n) {
c4++;
s[i] = '4';
i++;
}
break;
}
if (s[i] < '4') {
s[i] = '4';
c4++;
big = 1;
} else if (s[i] == '4')
c4++;
else if (s[i] < '7') {
s[i] = '7';
c7++;
big = 1;
} else if (s[i] == '7')
c7++;
else if (s[i] > '7') {
if (c7 == i) {
can = 0;
break;
}
int j = i - 1;
while (s[j] == '7') {
c7--;
j--;
}
s[j] = '7';
c4--;
c7++;
j++;
big = 1;
while (j < n) {
c4++;
s[j] = '4';
j++;
}
break;
}
}
if (!can || c4 == 0) {
n = (n + 2) / 2;
for (int i = 0; i < n; i++) putchar('4');
for (int i = 0; i < n; i++) putchar('7');
puts("");
continue;
}
if (c7 > c4) {
c7++;
c4--;
int j = n - 1;
for (; j >= 0; j--) {
if (c7 == c4) break;
if (s[j] == '7') {
c7--;
c4++;
s[j] = '4';
}
s[j] = '4';
}
if (j < 0)
can = 0;
else {
while (j >= 0 && s[j] == '7') --j;
if (j < 0)
can = 0;
else {
s[j] = '7';
sort(s + j + 1, s + n);
}
}
}
if (!can) {
n = (n + 2) / 2;
for (int i = 0; i < n; i++) putchar('4');
for (int i = 0; i < n; i++) putchar('7');
puts("");
continue;
}
int dt = (c4 - c7) / 2;
for (int i = n - 1; i >= 0; i--) {
if (dt == 0) break;
if (s[i] == '4') {
s[i] = '7';
dt--;
}
}
puts(s);
}
}
|
#include <bits/stdc++.h>
using namespace std;
long long max(long long a, long long b) {
if (a > b)
return a;
else
return b;
}
long long min(long long a, long long b) {
if (a < b)
return a;
else
return b;
}
long long mod = 1000000007;
string s;
int n;
map<int, int> f;
int calc(int i, char ans[]) {
if (i == n) return f[4] == f[7];
for (auto it : f) {
int x = s[i] - '0';
if (it.second > 0 and it.first >= x) {
f[it.first]--;
ans[i] = (it.first + '0');
if (it.first > x) {
int y = (n - i - 1 - abs(f[7] - f[4]));
if (y % 2 == 0) {
string s1;
if (f[4] > f[7])
s1 = string((f[4] - f[7] + y / 2), '4') + string(y / 2, '7');
else
s1 = string(y / 2, '4') + string((f[7] - f[4] + y / 2), '7');
int k = 0;
for (int j = i + 1; j < n; j++) {
ans[j] = s1[k];
k++;
}
return 1;
}
}
if (calc(i + 1, ans)) return 1;
f[it.first]++;
}
}
return 0;
}
bool test = 0;
void solve() {
cin >> s;
n = s.size();
if (n & 1) {
int x = (n + 1) / 2;
cout << string(x, '4') + string(x, '7');
return;
}
f[4] = n / 2;
f[7] = n / 2;
char ans[n];
if (calc(0, ans)) {
for (int i = 0; i < n; i++) cout << ans[i];
} else
cout << string(n / 2 + 1, '4') + string(n / 2 + 1, '7');
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
if (test) cin >> t;
while (t--) {
solve();
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string a;
string out;
int main() {
cin >> a;
if (a.size() % 2 == 1) {
int k = a.size() + 1;
for (int i = 0; i < k / 2; i++) cout << 4;
for (int i = 0; i < k / 2; i++) cout << 7;
cout << endl;
return 0;
}
for (int i = 0; i < a.size() / 2; i++) {
out += '7';
}
for (int i = 0; i < a.size() / 2; i++) {
out += '4';
}
if (out < a) {
int k = a.size() + 2;
for (int i = 0; i < k / 2; i++) cout << 4;
for (int i = 0; i < k / 2; i++) cout << 7;
cout << endl;
return 0;
}
int si = a.size() / 2;
int qi = a.size() / 2;
int zong = si + qi;
int jishu4 = 0, jishu7 = 0;
int ji = 0, ji2 = 0, jiq = 0;
string shu;
for (int i = 0; i < a.size(); i++) {
if (a[i] < '4') {
for (int j = 0; j < si + qi; j++) shu += '4', jishu4++;
break;
} else if (a[i] == '4') {
shu += '4';
jishu4++;
si--;
ji = i;
} else if (a[i] > '4' && a[i] < '7') {
shu += '7';
jishu7++;
jiq = i;
qi--;
for (int j = 0; j < si + qi; j++) shu += '4', jishu4++;
break;
} else if (a[i] == '7') {
shu += '7';
jishu7++;
jiq = i;
qi--;
} else if (a[i] > '7') {
shu[ji] = '7';
jishu7++;
jishu4--;
qi--;
si++;
for (int j = ji + 1; j < shu.size(); j++) {
if (shu[j] == '7') {
jishu7--;
jishu4++;
}
shu[j] = '4';
}
for (int j = 0; j < si + qi; j++) shu += '4', jishu4++;
break;
}
}
if (jishu4 == jishu7) {
cout << shu << endl;
return 0;
} else if (jishu4 > jishu7) {
for (int i = shu.size() - 1; i >= 0; i--) {
if (jishu4 == jishu7) {
cout << shu << endl;
return 0;
}
if (shu[i] == '4') {
shu[i] = '7';
jishu7++;
jishu4--;
}
if (jishu4 == jishu7) {
cout << shu << endl;
return 0;
}
}
} else if (jishu4 < jishu7) {
for (int i = shu.size() - 1; i >= 0; i--) {
int p = 0;
if (shu[i] == '4') {
for (int j = 0; j < i; j++) {
if (shu[j] == '4') p++;
}
if (p + (shu.size() - i - 1) >= shu.size() / 2) {
shu[i] = '7';
jishu7++;
jishu4--;
int shu4 = 0, shu7 = 0;
for (int j = i + 1; j < shu.size(); j++) {
if (jishu4 == jishu7) {
for (int k = i + 1; k <= i + shu4 + 1; k++) {
shu[k] = '4';
}
for (int k = i + shu4 + 2; k < shu.size(); k++) {
shu[k] = '7';
}
cout << shu << endl;
return 0;
}
if (shu[j] == '7') {
shu[j] = '4';
jishu7--;
jishu4++;
}
if (shu[j] == '4') shu4++;
if (shu[j] == '7') shu7++;
if (jishu4 == jishu7) {
cout << shu << endl;
return 0;
}
}
}
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string x, y;
bool gao(int i, int a, int b) {
if (a == 0 && b == 0) {
return true;
}
if (a > 0) {
y += '4';
if (x[i] < '4') {
y.insert(y.length(), a - 1, '4');
y.insert(y.length(), b, '7');
return true;
} else if (x[i] == '4' && gao(i + 1, a - 1, b)) {
return true;
} else {
y.erase(y.length() - 1);
}
}
if (b > 0) {
y += '7';
if (x[i] < '7') {
y.insert(y.length(), a, '4');
y.insert(y.length(), b - 1, '7');
return true;
} else if (x[i] == '7' && gao(i + 1, a, b - 1)) {
return true;
} else {
y.erase(y.length() - 1);
}
}
return false;
}
int main() {
cin >> x;
if (x.length() % 2 != 0) {
x = "0" + x;
}
while (true) {
y = "";
if (gao(0, x.length() / 2, x.length() / 2)) {
break;
}
x = "00" + x;
}
cout << y << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
void func(vector<string>& v, int a, int b, int n, int total, string s) {
if (total == n && a == b) {
v.push_back(s);
return;
}
if (total == n) return;
func(v, a + 1, b, n, total + 1, s + "4");
func(v, a, b + 1, n, total + 1, s + "7");
}
int main() {
string s;
cin >> s;
int n = s.length();
int flag = 1;
if (n % 2 == 0) {
flag = 2;
vector<string> v;
func(v, 0, 0, n, 0, "");
sort((v).begin(), (v).end());
for (auto item : v) {
if (item >= s) {
cout << item;
return 0;
}
}
}
n += flag;
n = n / 2;
for (int i = 0; i < n; i++) {
cout << 4;
}
for (int i = 0; i < n; i++) cout << 7;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string n, minx, maxn, ans;
int len;
int Dfs(int now, int num4, int num7, int flag) {
int i;
if (now >= len) return 1;
if (flag) {
for (i = 1; i <= num4; i++) ans.push_back('4');
for (i = 1; i <= num7; i++) ans.push_back('7');
return 1;
}
if (num4 && n[now] <= '4') {
ans.push_back('4');
if (Dfs(now + 1, num4 - 1, num7, n[now] < '4')) return 1;
ans.erase(ans.begin() + now);
}
if (num7 && n[now] <= '7') {
ans.push_back('7');
if (Dfs(now + 1, num4, num7 - 1, n[now] < '7')) return 1;
ans.erase(ans.begin() + now);
}
return 0;
}
int main() {
int i;
cin >> n;
len = n.size();
if (len % 2 == 1) {
int tot = len / 2 + 1;
ans.clear();
for (i = 1; i <= tot; i++) ans.push_back('4');
for (i = 1; i <= tot; i++) ans.push_back('7');
} else {
int tot = len / 2;
maxn.clear();
for (i = 1; i <= tot; i++) maxn.push_back('7');
for (i = 1; i <= tot; i++) maxn.push_back('4');
if (n > maxn) {
tot++;
ans.clear();
for (i = 1; i <= tot; i++) ans.push_back('4');
for (i = 1; i <= tot; i++) ans.push_back('7');
} else {
ans.clear();
int t = (Dfs(0, len / 2, len / 2, 0));
}
}
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
struct Nodo {
string txt;
int c_4;
int c_7;
Nodo() {}
Nodo(string texto, int C1, int C2) {
txt = texto;
c_4 = C1;
c_7 = C2;
}
bool operator<(const Nodo &refe) const {
if (txt.size() != refe.txt.size()) {
return (txt.size() > refe.txt.size());
} else {
return (txt > refe.txt);
}
}
};
int main() {
string algo;
cin >> algo;
priority_queue<Nodo> cola;
cola.push(Nodo("", 0, 0));
while (!cola.empty()) {
string txt = cola.top().txt;
int c1 = cola.top().c_4;
int c2 = cola.top().c_7;
cola.pop();
if (c1 == c2) {
if (txt.size() >= algo.size()) {
if (atoll(txt.c_str()) >= atoll(algo.c_str())) {
cout << txt << endl;
return 0;
}
}
}
if (txt.size() > algo.size() + 2) continue;
cola.push(Nodo(txt + "4", c1 + 1, c2));
cola.push(Nodo(txt + "7", c1, c2 + 1));
}
}
|
#include <bits/stdc++.h>
using namespace std;
const int M = 100050;
char s[M], tmp[M];
int pos[M], ct[M], cnt1, cnt2;
int main() {
scanf("%s", s);
int len = strlen(s);
bool flag = 0;
if (len & 1) {
for (int i = 0; i < (len + 1) >> 1; i++) printf("4");
for (int i = 0; i < (len + 1) >> 1; i++) printf("7");
return 0;
}
int i, ll = len >> 1;
for (i = 0; i < len; i++) {
if (s[i] <= '4') {
cnt1++;
if (cnt1 > ll) {
tmp[i] = '7';
cnt1--, cnt2++;
break;
} else {
tmp[i] = '4';
if (s[i] < '4') break;
pos[cnt1] = i;
ct[cnt1] = cnt2;
}
} else if (s[i] <= '7') {
cnt2++;
if (cnt2 > ll) {
while (cnt1 && ct[cnt1] >= ll) cnt1--;
if (cnt1 == 0) {
flag = 1;
break;
}
tmp[i = pos[cnt1]] = '7';
cnt2 = ct[cnt1--] + 1;
break;
} else {
tmp[i] = '7';
if (s[i] < '7') break;
}
} else {
while (cnt1 && ct[cnt1] >= ll) cnt1--;
if (cnt1 == 0) {
flag = 1;
break;
}
tmp[i = pos[cnt1]] = '7';
cnt2 = ct[cnt1--] + 1;
break;
}
}
if (flag) {
i = ll + 1;
while (i--) printf("4");
i = ll + 1;
while (i--) printf("7");
} else {
if (i == len) i--;
for (int j = 0; j <= i; j++) printf("%c", tmp[j]);
i = ll - cnt1;
while (i--) printf("4");
i = ll - cnt2;
while (i--) printf("7");
}
}
|
#include <bits/stdc++.h>
using namespace std;
int len;
string s;
char ans[100005];
bool dfs(int pos, int cnt4, int cnt7, bool flag) {
if (pos == len) return true;
if (flag) {
for (int i = 0; i < cnt4; i++) ans[pos++] = '4';
for (int i = 0; i < cnt7; i++) ans[pos++] = '7';
return true;
}
if (s[pos] <= '4' && cnt4) {
if (dfs(pos + 1, cnt4 - 1, cnt7, s[pos] < '4')) {
ans[pos] = '4';
return true;
}
}
if (s[pos] <= '7' && cnt7) {
if (dfs(pos + 1, cnt4, cnt7 - 1, s[pos] < '7')) {
ans[pos] = '7';
return true;
}
}
return false;
}
int main() {
cin >> s;
len = s.length();
if (len % 2 || !dfs(0, len / 2, len / 2, false)) {
len = len % 2 ? (len + 1) / 2 : (len + 2) / 2;
for (int i = 0; i < len; i++) cout << 4;
for (int i = 0; i < len; i++) cout << 7;
cout << endl;
}
cout << ans << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
long long n, s;
void dfs(long long x, int s4, int s7) {
if ((x >= n) && (s4 == s7) && ((x < s) || (s == 0))) s = x;
if (x < n * 100) {
dfs(x * 10 + 4, s4 + 1, s7);
dfs(x * 10 + 7, s4, s7 + 1);
}
}
int main() {
cin >> n;
dfs(0, 0, 0);
if (n == 0) s = 47;
cout << s;
}
|
#include <bits/stdc++.h>
using namespace std;
void print(char* t, int k) {
for (int i = 0; i < k; i++) t[i] = '4';
for (int i = 0; i < k; i++) t[i + k] = '7';
t[k + k] = 0;
}
void go2(char* s, int idx) {
int n = strlen(s);
int k = n / 2;
int se = 0;
int fo = 0;
for (int i = 0; i < idx; i++) {
if (s[i] == '4')
fo++;
else
se++;
}
for (int i = idx; i < n; i++) {
if (fo < k) {
s[i] = '4';
fo++;
} else {
s[i] = '7';
se++;
}
}
}
bool go(char* s) {
int n = strlen(s);
int se = 0;
int fo = 0;
if (n % 2 == 1) {
int k = n / 2 + 1;
print(s, k);
return true;
}
int k = n / 2;
for (int i = 0; i < n; i++) {
if (s[i] > '7') {
if (i == 0) {
print(s, k + 1);
return true;
}
s[i - 1]++;
s[i] = '0';
return false;
} else if (s[i] == '7') {
if (se < k) {
se++;
} else {
s[i - 1]++;
s[i] = '0';
return false;
}
} else if (s[i] > '4') {
if (se < k) {
s[i] = '7';
go2(s, i + 1);
return true;
} else {
s[i - 1]++;
s[i] = '0';
return false;
}
} else if (s[i] == '4') {
if (fo < k) {
fo++;
} else {
s[i] = '7';
go2(s, i + 1);
return true;
}
} else {
if (fo < k) {
s[i] = '4';
go2(s, i + 1);
return true;
} else {
s[i] = '7';
go2(s, i + 1);
return true;
}
}
}
return true;
}
void calc(char* s) {
while (!go(s))
;
}
bool test(long long m) {
while (m > 0) {
if (m % 10 == 4 || m % 10 == 7) {
m /= 10;
} else {
return false;
}
}
return true;
}
int main() {
char s[100010];
cin >> s;
calc(s);
cout << s << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char num[100010];
int cnt[100010], four[100010], seven[100010];
int main() {
scanf("%s", num + 1);
int len = strlen(num + 1), dl = len;
if (dl & 1)
dl++;
else {
for (int i = 1; i <= dl; i++) {
int digit = (i <= dl / 2 ? 7 : 4);
if (digit < num[i] - '0') {
dl += 2;
break;
} else if (digit > num[i] - '0') {
break;
}
}
}
if (dl > len) {
for (int i = 1; i <= dl; i++) {
int digit = (i <= dl / 2 ? 4 : 7);
printf("%d", digit);
}
} else {
int pos = -1, digit;
for (int i = 1; i <= dl; i++) {
four[i] = four[i - 1];
seven[i] = seven[i - 1];
cnt[i] = cnt[i - 1];
if (num[i] == '4')
four[i]++;
else if (num[i] == '7')
seven[i]++;
else
cnt[i]++;
}
if (four[dl] == dl / 2 && four[dl] == seven[dl])
puts(num + 1);
else {
for (int i = dl; i >= 1; i--) {
if (num[i] < '7' && cnt[i - 1] == 0 && seven[i - 1] + 1 <= dl / 2 &&
four[i - 1] <= dl / 2) {
pos = i;
digit = 7;
}
if (num[i] < '4' && cnt[i - 1] == 0 && seven[i - 1] <= dl / 2 &&
four[i - 1] + 1 <= dl / 2) {
pos = i;
digit = 4;
}
if (pos != -1) break;
}
int a = dl / 2, b = dl / 2;
for (int i = 1; i <= dl; i++) {
if (i < pos) {
putchar(num[i]);
if (num[i] == '4')
a--;
else
b--;
} else if (i == pos) {
printf("%d", digit);
if (digit == 4)
a--;
else
b--;
} else {
if (a > 0)
printf("4"), a--;
else
printf("7"), b--;
}
}
puts("");
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char str[100100], ans[100100];
int len, num4, num7;
bool solve(int i) {
if (num4 == 0 && num7 == 0) {
ans[i] == '\0';
return true;
}
if (str[i] < '4' && num4 > 0) {
ans[i] = '4', num4--;
ans[i + 1] = '\0';
return true;
}
if (str[i] == '4' && num4 > 0) {
ans[i] = '4', num4--;
if (solve(i + 1)) return true;
num4++;
}
if (str[i] < '7' && num7 > 0) {
ans[i] = '7', num7--;
ans[i + 1] = '\0';
return true;
}
if (str[i] == '7' && num7 > 0) {
ans[i] = '7', num7--;
if (solve(i + 1)) return true;
num7++;
}
return false;
}
int main() {
while (scanf("%s", str) > 0) {
len = strlen(str);
num4 = (len + 1) / 2, num7 = (len + 1) / 2;
if (len % 2 == 0)
if (solve(0)) {
printf("%s", ans);
} else
num4++, num7++;
while (num4--) printf("4");
while (num7--) printf("7");
cout << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s;
char res[100010];
int len;
int func(int cur, int n4, int n7, int prev) {
if (cur == len) {
for (int i = (0), _n = (len); i < _n; i++) printf("%c", res[i]);
cout << endl;
return 1;
} else {
if (prev) {
if (n4) {
res[cur] = '4';
return func(cur + 1, n4 - 1, n7, 1);
}
res[cur] = '7';
return func(cur + 1, n4, n7 - 1, 1);
} else {
if (s[cur] <= '4' && n4) {
res[cur] = '4';
int flag = 0;
if (s[cur] < '4') flag = 1;
int val = func(cur + 1, n4 - 1, n7, flag);
if (val) return 1;
}
if (s[cur] <= '7' && n7) {
res[cur] = '7';
int flag = 0;
if (s[cur] < '7') flag = 1;
int val = func(cur + 1, n4, n7 - 1, flag);
if (val) return 1;
}
}
}
return 0;
}
int main() {
cin >> s;
len = s.size();
if (len % 2 == 1) {
len++;
for (int i = (0), _n = (len / 2); i < _n; i++) printf("4");
for (int i = (0), _n = (len / 2); i < _n; i++) printf("7");
cout << endl;
return 0;
} else {
int n4 = len / 2;
int n7 = len / 2;
int val = func(0, n4, n7, 0);
if (!val) {
len += 2;
for (int i = (0), _n = (len / 2); i < _n; i++) printf("4");
for (int i = (0), _n = (len / 2); i < _n; i++) printf("7");
cout << endl;
return 0;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int ml = 100005;
string n;
int len, len2;
bool go1() {
for (int i = 0; i < len2; i++) {
if (n[i] < '7') return 1;
if (n[i] > '7') return 0;
}
for (int i = len2; i < len; i++) {
if (n[i] < '4') return 1;
if (n[i] > '4') return 0;
}
return 1;
}
int main() {
cin >> n;
len = n.size();
if (len & 1) {
n = "1";
for (int i = 0; i < len; i++) n.push_back('0');
len++;
}
len2 = len / 2;
if (!go1()) {
len += 2;
len2 += 1;
n = "1";
for (int i = 0; i < len - 1; i++) n.push_back('0');
}
int rem4 = len2, rem7 = len2;
bool lesser = 0;
string ans;
for (int i = 0; i < len; i++) ans.push_back('7');
for (int i = 0; i < len; i++) {
if (lesser) {
if (rem4)
ans[i] = '4', rem4--;
else
ans[i] = '7', rem7--;
} else {
if (n[i] <= '4' && rem4) {
ans[i] = '4', rem4--;
if (n[i] < '4') lesser = 1;
} else if (n[i] <= '7' && rem7) {
ans[i] = '7', rem7--;
if (n[i] < '7') lesser = 1;
} else {
int j;
for (j = i - 1; j >= 0; j--) {
if (ans[j] != '4')
rem7++;
else {
if (rem7 > 0)
break;
else
rem4++;
}
}
ans[j] = '7';
lesser = 1;
rem4++;
rem7--;
i = j;
}
}
}
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
set<long long> num;
void f(int x, int a, int b, long long now) {
if (x == 0) {
num.insert(now);
return;
}
if (a) f(x - 1, a - 1, b, now * 10 + 4);
if (b) f(x - 1, a, b - 1, now * 10 + 7);
}
void init() {
int i;
for (i = 1; i <= 5; i++) f(i * 2, i, i, 0LL);
}
int main() {
long long n;
init();
scanf("%I64d", &n);
printf("%I64d", *num.upper_bound(n - 1));
}
|
#include <bits/stdc++.h>
using namespace std;
vector<long long> lucky;
void nums(long long number, int fours, int sevens) {
if (number > 1e10) return;
if (fours == sevens) lucky.push_back(number);
nums(number * 10 + 7, fours, sevens + 1);
nums(number * 10 + 4, fours + 1, sevens);
}
int main() {
nums(4, 1, 0);
nums(7, 0, 1);
long long n;
cin >> n;
sort(lucky.begin(), lucky.end());
cout << lucky[lower_bound(lucky.begin(), lucky.end(), n) - lucky.begin()]
<< endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
vector<long long> v;
void lucky(long long z) {
if (z > 1e10) return;
if (z) v.push_back(z);
lucky(z * 10 + 4);
lucky(z * 10 + 7);
}
int main() {
lucky(0);
sort(v.begin(), v.end());
long long n;
cin >> n;
for (long long i = 0; i < v.size(); i++) {
if (v[i] >= n) {
long long temp = v[i], four = 0, seven = 0;
while (temp != 0) {
if (temp % 10 == 4)
four++;
else
seven++;
temp /= 10;
}
if (four == seven) {
cout << v[i];
return 0;
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int maxn = 100100;
int n;
char a[maxn], b[maxn];
bool dfs(int step, int n4, int n7, bool large) {
if (step == n) return puts(b), true;
if (large)
if (n4)
return b[step] = '4', dfs(step + 1, n4 - 1, n7, large);
else
return b[step] = '7', dfs(step + 1, n4, n7 - 1, large);
if (n4 > 0 && a[step] <= '4') {
b[step] = '4';
if (dfs(step + 1, n4 - 1, n7, a[step] < '4')) return true;
}
if (n7 > 0 && a[step] <= '7') {
b[step] = '7';
if (dfs(step + 1, n4, n7 - 1, a[step] < '7')) return true;
}
return false;
}
int main() {
scanf("%s", a);
n = strlen(a);
if (n % 2 == 1 || !dfs(0, n / 2, n / 2, false)) {
n = n / 2 + 1;
for (int i = 1; i <= n; i++) printf("4");
for (int i = 1; i <= n; i++) printf("7");
printf("\n");
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
bool flag;
int len;
string ori, tmp, ans;
void dfs(string s, int req, int cnt) {
if (flag) return;
if (s.length() == req) {
if (cnt == s.length() / 2) {
if (s.length() > ori.length() || s >= ori) {
ans = s;
flag = 1;
}
}
return;
}
dfs(s + "4", req, cnt + 1);
dfs(s + "7", req, cnt);
}
int main() {
flag = 0;
cin >> ori;
len = ori.length();
if (len % 2) {
dfs("4", len + 1, 1);
dfs("7", len + 1, 0);
} else {
dfs("4", len, 1);
dfs("7", len, 0);
if (!flag) {
dfs("4", len + 2, 1);
dfs("7", len + 2, 0);
}
}
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long int tt;
vector<long long int> ans;
vector<long long int> a;
long long int x, y;
bool fun(long long int idx, bool check) {
if (idx >= a.size()) {
return true;
}
if (check) {
if (x > 0) {
ans.push_back(4);
x--;
return fun(idx + 1, check);
} else {
ans.push_back(7);
y--;
return fun(idx + 1, check);
}
} else {
if (a[idx] > 7) {
return false;
}
if (a[idx] < 4) {
if (x > 0) {
ans.push_back(4);
x--;
} else {
ans.push_back(7);
y--;
}
for (long long int i = 0; i < x; i++) {
ans.push_back(4);
}
for (long long int i = 0; i < y; i++) {
ans.push_back(7);
}
return true;
} else if (a[idx] == 4) {
bool check1 = false;
if (x > 0) {
ans.push_back(4);
x--;
check1 = fun(idx + 1, check);
}
if (check1 == false) {
ans.pop_back();
x++;
if (y > 0) {
ans.push_back(7);
y--;
for (long long int i = 0; i < x; i++) {
ans.push_back(4);
}
for (long long int i = 0; i < y; i++) {
ans.push_back(7);
}
return true;
} else {
return false;
}
}
return check1;
} else {
if (y <= 0) {
return false;
}
ans.push_back(7);
y--;
if (a[idx] == 7) {
bool check1 = fun(idx + 1, false);
if (check1 == false) {
y++;
ans.pop_back();
}
return check1;
} else {
for (long long int i = 0; i < x; i++) {
ans.push_back(4);
}
for (long long int i = 0; i < y; i++) {
ans.push_back(7);
}
return true;
}
}
}
return false;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
string ch;
cin >> ch;
long long int n = ch.length();
a.resize(n);
for (long long int i = 0; i < n; i++) {
a[i] = ch[i] - '0';
}
x = n / 2 + n % 2;
y = x;
if (n % 2) {
for (long long int i = 0; i < x; i++) {
cout << 4;
}
for (long long int i = 0; i < x; i++) {
cout << 7;
}
cout << endl;
} else {
bool check = fun(0, false);
if (check) {
for (long long int i = 0; i < ans.size(); i++) {
cout << ans[i];
}
cout << endl;
} else {
x++;
for (long long int i = 0; i < x; i++) {
cout << 4;
}
for (long long int i = 0; i < x; i++) {
cout << 7;
}
cout << endl;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int inf(1010101010);
int le;
string s;
bool kan_gelijk(int cnt) {
string t;
int r4(le / 2), r7(le / 2);
for (int i(0); i < (cnt); i++) {
if (s[i] != '4' && s[i] != '7') return false;
if (s[i] == '4') t += '4', r4--;
if (s[i] == '7') t += '7', r7--;
}
if (r4 < 0 || r7 < 0) return false;
while (r7) t += '7', r7--;
while (r4) t += '4', r4--;
return t >= s;
}
void pr(int cnt) {
string t;
int r4(le / 2), r7(le / 2);
for (int i(0); i < (cnt); i++) {
if (s[i] == '4') t += '4', r4--;
if (s[i] == '7') t += '7', r7--;
}
if (cnt < le) {
if (s[cnt] < '4' && r4)
t += '4', r4--;
else
t += '7', r7--;
}
while (r4) t += '4', r4--;
while (r7) t += '7', r7--;
cout << t << endl;
}
int main() {
cin >> s;
le = ((int)(s).size());
if (le % 2 == 1) {
string t;
for (int i(0); i < ((le + 1) / 2); i++) t += '4';
for (int i(0); i < ((le + 1) / 2); i++) t += '7';
cout << t << endl;
} else {
string tmp;
for (int i(0); i < (le / 2); i++) tmp += '7';
for (int i(0); i < (le / 2); i++) tmp += '4';
if (tmp < s) {
string t;
for (int i(0); i < (1 + le / 2); i++) t += '4';
for (int i(0); i < (1 + le / 2); i++) t += '7';
cout << t << endl;
} else {
int lo(0), hi(le);
while (lo - hi) {
int mi((lo + hi + 1) / 2);
if (kan_gelijk(mi))
lo = mi;
else
hi = mi - 1;
}
pr(lo);
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
string a;
string ans = "", x = "";
bool Judge() {
if (a.size() % 2) {
return false;
}
string temp = "";
for (int i = 0; i < a.size(); i++) {
if (i < a.size() / 2) {
temp += "7";
} else {
temp += "4";
}
}
return temp >= a;
}
void Deal() {
int t = a.size();
t = t % 2 ? t + 1 : t + 2;
for (int i = 0; i < t; i++) {
if (i < t / 2) {
ans += "4";
} else {
ans += "7";
}
}
return;
}
void Dfs(int num4, int num7, int pos, bool flag) {
if (ans != "") {
return;
}
if (x < a.substr(0, x.size())) {
return;
}
if (num4 > a.size() / 2 || num7 > a.size() / 2) {
return;
}
if (x.size() == a.size()) {
if (num4 == num7 && x >= a) {
if (x < ans || ans == "") {
ans = x;
return;
}
}
}
if (flag == true) {
ans = x;
while (num4 < a.size() / 2) {
ans += '4';
num4++;
}
while (num7 < a.size() / 2) {
ans += '7';
num7++;
}
return;
}
if (a[pos] <= '4') {
x += "4";
Dfs(num4 + 1, num7, pos + 1, (a[pos] != '4'));
x.erase(x.size() - 1, 1);
}
if (a[pos] <= '7') {
x += "7";
Dfs(num4, num7 + 1, pos + 1, (a[pos] != '7'));
x.erase(x.size() - 1, 1);
}
return;
}
int main() {
cin >> a;
if (Judge()) {
Dfs(0, 0, 0, false);
} else {
Deal();
}
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
vector<int> next_p(vector<int> s) {
vector<int> ss = s;
int I = -1, J = -1;
for (int i = s.size() - 1; i >= 0; i--) {
if (s[i] == 7) {
I = i;
break;
}
}
for (int j = I - 1; j >= 0; j--) {
if (s[j] == 4) {
J = j;
break;
}
}
if (I == -1 || J == -1)
return s;
else {
int tmp = ss[I];
ss[I] = ss[J];
ss[J] = tmp;
sort(ss.begin() + J + 1, ss.end());
}
return ss;
}
int grt(string s, string t) {
if (s.size() > t.size())
return 1;
else if (s.size() < t.size())
return 2;
for (int i = (int)0; i < (int)s.size(); ++i) {
if (s[i] - '0' > t[i] - '0')
return 1;
else if (s[i] - '0' < t[i] - '0')
return 2;
}
return 2;
}
string smallest_given(int n, int fours, int sevens) {
string s("");
for (int i = (int)0; i < (int)(n / 2) - fours; ++i) s += '4';
for (int i = (int)0; i < (int)(n / 2) - sevens; ++i) s += '7';
return s;
}
string smallest(int n) {
string s("");
for (int i = (int)0; i < (int)n / 2; ++i) s += '4';
for (int i = (int)0; i < (int)n / 2; ++i) s += '7';
return s;
}
string next(string s) {
int fr = 0;
int sv = 0;
vector<int> vv, nn;
for (int i = (int)0; i < (int)s.size(); ++i) {
if (s[i] == '4') {
fr++;
vv.push_back(4);
} else if (s[i] == '7') {
sv++;
vv.push_back(7);
}
}
if (fr == sv)
return s;
else {
nn = next_p(vv);
int fg = 0;
if (vv == nn) {
if (vv[0] == 4) {
return smallest(vv.size());
} else {
return smallest(vv.size() + 2);
}
} else {
if (fr > sv) {
int j = 0;
for (int i = vv.size() - 1; i >= 0; i--) {
if (vv[i] == 4) {
vv[i] = 7;
fr--;
sv++;
}
if (fr == sv) break;
}
} else {
for (int i = vv.size() - 1; i >= 0; i--) {
if (vv[i] == 7) {
vv[i] = 4;
fr++;
sv--;
}
if (fr == sv) break;
}
vv = next_p(vv);
}
string t;
for (int i = (int)0; i < (int)vv.size(); ++i) {
if (vv[i] == 4)
t += '4';
else if (vv[i] == 7)
t += '7';
}
return t;
}
}
}
int main() {
string s;
cin >> s;
vector<int> v, v_next;
if (s.size() % 2 == 0) {
string sofar("");
int fours = 0;
int sevens = 0;
if (s[0] - '0' > 7) {
sofar += smallest(s.size() + 2);
} else {
for (int i = (int)0; i < (int)s.size(); ++i) {
if ((s[i] - '0') < 4) {
sofar += smallest_given(s.size(), fours, sevens);
break;
} else if (s[i] == '4') {
sofar += '4';
v.push_back(4);
fours++;
} else if (s[i] == '5' || s[i] == '6') {
sofar += '7';
sevens++;
sofar += smallest_given(s.size(), fours, sevens);
break;
} else if (s[i] == '7') {
sofar += '7';
sevens++;
v.push_back(7);
} else if (s[i] - '0' > 7) {
v_next = next_p(v);
int fg = 0;
if (v == v_next) {
if (v[0] == 4) {
v[v.size() - 1] = 7;
fours--;
sevens++;
} else {
fg = 1;
v.clear();
for (int i = (int)0; i < (int)v_next.size() + 1; ++i)
v.push_back(4);
fours = v_next.size() + 1;
sevens = 0;
}
} else {
}
sofar = "";
for (int i = (int)0; i < (int)v.size(); ++i) {
if (v[i] == 4)
sofar += '4';
else
sofar += '7';
}
if (fg == 1) {
sofar = smallest_given(s.size() + 2, 0, 0);
} else {
sofar += smallest_given(s.size(), fours, sevens);
if (grt(sofar, s) == 2) {
v.clear();
for (int i = (int)0; i < (int)sofar.size(); ++i) {
v.push_back(sofar[i] - '0');
}
v = next_p(v);
sofar = "";
for (int i = (int)0; i < (int)v.size(); ++i) {
if (v[i] == 4)
sofar += '4';
else
sofar += '7';
}
}
}
break;
}
}
}
cout << next(sofar) << endl;
} else {
cout << smallest(s.size() + 1) << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
const int N = 1e5 + 50;
char s[N];
int lens, ok;
int ws[N];
void dfs(int now, int _4, int _7) {
if (now == lens) {
for (int i = 0; i < lens; i++) putchar(ws[i] + 48);
ok = 1;
return;
}
if (!ok)
if (s[now] < '4') {
if (_4)
ws[now] = 4, _4--;
else
ws[now] = 7, _7--;
for (int i = 0; i <= now; i++) putchar(ws[i] + 48);
for (int i = 1; i <= _4; i++) putchar('4');
for (int i = 1; i <= _7; i++) putchar('7');
ok = 1;
return;
}
if (!ok)
if (s[now] == '4') {
if (_4) {
ws[now] = 4, _4--;
dfs(now + 1, _4, _7);
_4++;
}
if (!ok)
if (_7) {
ws[now] = 7, _7--;
for (int i = 0; i <= now; i++) putchar(ws[i] + 48);
for (int i = 1; i <= _4; i++) putchar('4');
for (int i = 1; i <= _7; i++) putchar('7');
ok = 1;
return;
} else
return;
}
if (!ok)
if (s[now] < '7') {
if (_7) {
ws[now] = 7, _7--;
for (int i = 0; i <= now; i++) putchar(ws[i] + 48);
for (int i = 1; i <= _4; i++) putchar('4');
for (int i = 1; i <= _7; i++) putchar('7');
ok = 1;
return;
} else
return;
}
if (!ok)
if (s[now] == '7') {
if (_7) {
ws[now] = 7, _7--;
dfs(now + 1, _4, _7);
_7++;
} else
return;
}
if (!ok)
if (s[now] > '7') return;
return;
}
int main() {
scanf("%s", s);
lens = strlen(s);
if (lens & 1) {
for (int i = 0; i <= lens / 2; i++) putchar('4');
for (int i = lens / 2; i < lens; i++) putchar('7');
return 0;
}
if (s[0] < '4') {
for (int i = 0; i < lens / 2; i++) putchar('4');
for (int i = lens / 2; i < lens; i++) putchar('7');
return 0;
}
if (s[0] == '4') {
ws[0] = 4;
dfs(1, lens / 2 - 1, lens / 2);
if (!ok) {
putchar('7');
for (int i = 0; i < lens / 2; i++) putchar('4');
for (int i = lens / 2 + 1; i < lens; i++) putchar('7');
return 0;
}
return 0;
}
if (s[0] < '7') {
putchar('7');
for (int i = 0; i < lens / 2; i++) putchar('4');
for (int i = lens / 2 + 1; i < lens; i++) putchar('7');
return 0;
}
if (s[0] == '7') {
ws[0] = 7;
dfs(1, lens / 2, lens / 2 - 1);
if (!ok) {
putchar('4');
for (int i = 0; i < lens / 2; i++) putchar('4');
for (int i = lens / 2; i < lens; i++) putchar('7');
putchar('7');
return 0;
}
return 0;
}
if (s[0] > '7') {
putchar('4');
for (int i = 0; i < lens / 2; i++) putchar('4');
for (int i = lens / 2; i < lens; i++) putchar('7');
putchar('7');
return 0;
}
}
|
#include <bits/stdc++.h>
using namespace std;
long long int n;
long long int res = 1000000000000000;
int ass[16];
void check(int c1, int c2, long long int prev) {
if (prev < 9000000000000) {
if (c1 == c2) {
if (prev >= n) res = min(res, prev);
}
long long int val1 = (prev * (long long int)10) + (long long int)4;
check(c1 + 1, c2, val1);
val1 = (prev * (long long int)10) + (long long int)7;
check(c1, c2 + 1, val1);
}
}
int main() {
cin >> n;
check(0, 0, 0);
cout << res << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100100];
char A[100100];
int f[100100], g[100100], ff[100100], gg[100100];
int n;
void print(int a, int b, int p) {
for (int i = a; i < n / 2; i++) A[p++] = '4';
for (int i = b; i < n / 2; i++) A[p++] = '7';
A[p] = 0;
puts(A);
}
bool can(int a, int b, int p) {
if (a > n / 2 || b > n / 2) return 0;
b = n / 2 - b;
a = n / 2 - a;
if (b) {
if (f[p] - p < b) {
if (g[p] == f[p]) return 0;
return 1;
}
}
if (a) {
p += b;
if (ff[p] - p < a && ff[p] == gg[p]) return 0;
}
return 1;
}
int main() {
scanf("%s", s);
n = strlen(s);
int a = 0, b = 0;
if (n & 1) {
for (int i = 0; i <= n / 2; i++) putchar('4');
for (int i = 0; i <= n / 2; i++) putchar('7');
puts("");
return 0;
}
int cf = n, cg = n;
for (int i = n - 1; i >= 0; i--) {
if (s[i] != '7') cf = i;
if (s[i] > '7') cg = i;
f[i] = cf;
g[i] = cg;
}
cf = n, cg = n;
for (int i = n - 1; i >= 0; i--) {
if (s[i] != '4') cf = i;
if (s[i] > '4') cg = i;
ff[i] = cf;
gg[i] = cg;
}
int ok = 1;
for (int i = 0; i < n; i++) {
if (s[i] < '4' && a + 1 - b <= n - i - 1) {
A[i] = '4';
print(a + 1, b, i + 1);
return 0;
}
if (s[i] == '4') {
A[i] = '4';
if (can(a + 1, b, i + 1)) {
a++;
continue;
}
}
if (s[i] < '7' && b + 1 - a <= n - i - 1) {
A[i] = '7';
print(a, b + 1, i + 1);
return 0;
}
if (s[i] == '7') {
A[i] = '7';
if (can(a, b + 1, i + 1)) {
b++;
continue;
}
}
ok = 0;
break;
}
if (ok) {
A[n] = 0;
puts(A);
return 0;
}
for (int i = 0; i <= n / 2; i++) putchar('4');
for (int i = 0; i <= n / 2; i++) putchar('7');
puts("");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 100500;
const unsigned long long PW = 337;
unsigned long long pw[N], hs[N], ht[N];
void calcPW() {
pw[0] = 1;
for (int i = 1; i < N; i++) {
pw[i] = pw[i - 1] * PW;
}
}
void calcH(char* s, unsigned long long* h, int n) {
h[0] = 0;
for (int i = 1; i <= n; i++) {
h[i] = h[i - 1] + s[i - 1] * pw[i - 1];
}
}
int sgn(int x) { return x < 0 ? -1 : (x > 0 ? 1 : 0); }
unsigned long long getHash(unsigned long long* h, int l, int r) {
return (h[r] - h[l - 1]) * pw[N - l - 3];
}
int lcp(unsigned long long* h1, unsigned long long* h2, int l1, int r1, int l2,
int r2) {
int l = 0, r = min(r1 - l1 + 1, r2 - l2 + 1) + 1;
while (r - l > 1) {
int mid = (l + r) >> 1;
if (getHash(h1, l1, l1 + mid - 1) == getHash(h2, l2, l2 + mid - 1))
l = mid;
else
r = mid;
}
return l;
}
int compare(char* s1, unsigned long long* h1, char* s2, unsigned long long* h2,
int l1, int r1, int l2, int r2) {
int comm = lcp(h1, h2, l1, r1, l2, r2);
char a = (l1 + comm == r1 + 1 ? '\0' : s1[l1 + comm - 1]);
char b = (l2 + comm == r2 + 1 ? '\0' : s2[l2 + comm - 1]);
return sgn((int)a - (int)b);
}
char s[N];
char t[N];
int n, half, half2;
void getLR47(int k4, int k7, int& l, int& r) {
l = half - k7;
r = l + (k4 + k7) - 1;
l++, r++;
}
int main() {
calcPW();
scanf("%s", s);
n = strlen(s);
half = ((n + 1) / 2);
half2 = half * 2;
for (int i = 0; i < half; i++) {
t[i] = '7';
t[i + half] = '4';
}
calcH(s, hs, n);
calcH(t, ht, half2);
if (n % 2 == 1) {
n++;
for (int i = 0; i < n / 2; i++) {
putchar('4');
}
for (int i = 0; i < n / 2; i++) {
putchar('7');
}
puts("");
exit(0);
}
int l, r;
getLR47(n / 2, n / 2, l, r);
if (compare(s, hs, t, ht, 1, n, l, r) == 1) {
n += 2;
n++;
for (int i = 0; i < n / 2; i++) {
putchar('4');
}
for (int i = 0; i < n / 2; i++) {
putchar('7');
}
puts("");
exit(0);
}
int k4 = n / 2, k7 = n / 2;
for (int i = 0; i < n; i++) {
if (s[i] == '4' && k4 > 0) {
getLR47(k4 - 1, k7, l, r);
if (compare(s, hs, t, ht, i + 2, n, l, r) <= 0) {
s[i] = '4';
k4--;
continue;
}
}
if (s[i] == '7' && k7 > 0) {
getLR47(k4, k7 - 1, l, r);
if (compare(s, hs, t, ht, i + 2, n, l, r) <= 0) {
s[i] = '7';
k7--;
continue;
}
}
if (s[i] < '4') {
for (int j = i; j < n; j++) {
if (k4 > 0)
s[j] = '4', k4--;
else
s[j] = '7', k7--;
}
} else if (s[i] < '7') {
s[i] = '7', k7--;
for (int j = i + 1; j < n; j++) {
if (k4 > 0)
s[j] = '4', k4--;
else
s[j] = '7', k7--;
}
}
break;
}
puts(s);
puts("");
}
|
#include <bits/stdc++.h>
using namespace std;
long long ma = 0, f = 100000000000, x;
long long creat(short d, bool x) {
long long nu = 0;
short i;
for (i = 0; i < d / 2; i++) nu *= 10, nu += (4 * !x + 7 * x);
for (i = 0; i < d / 2; i++) nu *= 10, nu += (4 * x + 7 * !x);
return nu;
}
void re(short d, short d4, long long ans = 0) {
if (!d) {
if (f > ans - x && ans - x >= 0) {
ma = ans;
f = ans - x;
}
return;
}
if (d4) re(d - 1, d4 - 1, ans * 10 + 4);
if (d - d4) re(d - 1, d4, ans * 10 + 7);
}
int main() {
short di;
cin >> x;
di = log10((double)x);
di++;
if (di & 1)
cout << creat(di + 1, 0) << endl;
else if (creat(di, 1) >= x) {
re(di, di / 2);
cout << ma << endl;
} else
cout << creat(di + 2, 0) << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s, t, ans;
void f(int d, int x, int y, bool g) {
if (x > s.size() / 2 || y > s.size() / 2) return;
if (d == s.size()) {
ans = t;
return;
}
if (g) {
t[d] = '4';
f(d + 1, x + 1, y, 1);
if (ans != "") return;
t[d] = '7';
f(d + 1, x, y + 1, 1);
} else {
if (s[d] <= '4') {
t[d] = '4';
f(d + 1, x + 1, y, s[d] < '4');
if (ans != "") return;
}
if (s[d] <= '7') {
t[d] = '7';
f(d + 1, x, y + 1, s[d] < '7');
}
}
}
int main() {
ios_base::sync_with_stdio(false);
cin >> s;
for (int i = 0; i < s.size() / 2; i++) {
t += '7';
}
for (int i = 0; i < s.size() / 2; i++) {
t += '4';
}
if (s.size() % 2 || s > t) {
t = "";
for (int i = 0; i < s.size() / 2 + 1; i++) {
t += '4';
}
for (int i = 0; i < s.size() / 2 + 1; i++) {
t += '7';
}
cout << t;
return 0;
}
t = s;
f(0, 0, 0, 0);
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
inline bool eq(double a, double b) { return fabs(a - b) < 1e-9; }
const long long int inf = 1e15;
inline int two(int n) { return 1 << n; }
inline int test(int n, int b) { return (n >> b) & 1; }
inline void set_bit(int& n, int b) { n |= two(b); }
inline void unset_bit(int& n, int b) { n &= ~two(b); }
inline int last_bit(int n) { return n & (-n); }
inline int ones(int n) {
int res = 0;
while (n && ++res) n -= n & (-n);
return res;
}
string str;
string sol(int n) {
string ans;
for (int i = (0); i < (n); i++) {
ans = ans + (i < n / 2 ? "4" : "7");
}
return ans;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> str;
int n = str.length();
if (n & 1) {
cout << sol(n + 1) << endl;
} else {
int ind = -1, c4 = 0, c7 = 0;
for (int i = (0); i < (n); i++) {
if (str[i] > '7') {
if (ind == -1) {
cout << sol(n + 2) << endl;
return 0;
} else {
str[ind] = '7';
str[i] = '4';
c7++;
if (abs(c4 - c7) > n - i - 1) {
cout << sol(n + 2) << endl;
return 0;
} else {
int j = i + 1;
for (int k = (j); k < (n); k++) {
str[k] = '4';
c4++;
}
for (int k = (n - 1); k >= (i + 1); k--) {
if (c4 > c7) {
str[k] = '7';
c4--;
c7++;
} else {
break;
}
}
cout << str << endl;
return 0;
}
}
} else if (str[i] != '4' && str[i] != '7') {
if (str[i] < '4') {
str[i] = '4';
c4++;
} else {
str[i] = '7';
c7++;
}
if (abs(c4 - c7) > n - i - 1) {
cout << sol(n + 2) << endl;
return 0;
} else {
int j = i + 1;
for (int k = (j); k < (n); k++) {
str[k] = '4';
c4++;
}
for (int k = (n - 1); k >= (i + 1); k--) {
if (c4 > c7) {
str[k] = '7';
c4--;
c7++;
} else {
break;
}
}
cout << str << endl;
return 0;
}
} else {
if (str[i] == '4') {
ind = i;
c4++;
} else
c7++;
}
}
if (c4 > c7) {
for (int i = (ind); i >= (0); i--) {
if (c4 > c7) {
str[i] = '7';
c4--;
c7++;
} else {
break;
}
}
cout << str << endl;
} else if (c7 > c4) {
int cc4 = 0, cc7 = 0;
for (int i = 0; i <= ind; i++) {
if (str[i] == '4')
cc4++;
else
cc7++;
}
c4 = cc4, c7 = cc7;
for (int i = (ind); i >= (0); i--) {
if (str[i] == '4') {
if (abs(c4 - c7 - 1) <= n - i - 1) {
str[i] = '7';
c4--;
c7++;
int j = i + 1;
for (int k = (j); k < (n); k++) {
str[k] = '4';
c4++;
}
for (int k = (n - 1); k >= (i + 1); k--) {
if (c4 > c7) {
str[k] = '7';
c4--;
c7++;
} else {
break;
}
}
cout << str << endl;
return 0;
}
c4--;
} else {
c7--;
}
}
cout << sol(n + 2) << endl;
} else {
cout << str << endl;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
bool cmp(long long a, long long b) { return (a > b); }
long long ceil(const long long &a, const long long &b) {
if (a % b == 0) return a / b;
return a / b + 1;
}
long long mod = 1000000007;
const long long N = 200005;
long long go(string s) {
stringstream geek(s);
long long x = 0;
geek >> x;
return x;
}
long long n;
string s;
char res1[N];
void solve(long long i, long long f, long long x, long long y) {
if (i >= n) {
cout << res1;
exit(0);
}
if ((s[i] - '0') < 4) {
if (x) {
res1[i] = '4';
solve(i + 1, 1, x - 1, y);
}
if (y) {
res1[i] = '7';
solve(i + 1, 1, x, y - 1);
}
} else if ((s[i] - '0') == 4) {
if (x) {
res1[i] = '4';
solve(i + 1, f, x - 1, y);
}
if (y) {
res1[i] = '7';
solve(i + 1, 1, x, y - 1);
}
} else if ((s[i] - '0') < 7) {
if (f && x) {
res1[i] = '4';
solve(i + 1, 1, x - 1, y);
}
if (y) {
res1[i] = '7';
solve(i + 1, 1, x, y - 1);
}
} else if ((s[i] - '0') == 7) {
if (f && x) {
res1[i] = '4';
solve(i + 1, 1, x - 1, y);
}
if (y) {
res1[i] = '7';
solve(i + 1, f, x, y - 1);
}
} else {
if (f && x) {
res1[i] = '4';
solve(i + 1, 1, x - 1, y);
}
if (f && y) {
res1[i] = '7';
solve(i + 1, 1, x, y - 1);
}
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> s;
string res = "";
n = s.size();
long long flag = 1;
if (n % 2 == 0) {
long long x = n / 2;
long long y = n / 2;
long long f = 0;
solve(0, 0, x, y);
}
if (n % 2 == 0) {
n++;
}
if (n % 2) {
res = "";
for (long long i = 0; i < n / 2 + 1; i++) {
res += '4';
}
for (long long i = 0; i < n / 2 + 1; i++) {
res += '7';
}
cout << res;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char str[100005];
int flag[100005];
void print(int len) {
for (int i = 0; i < len / 2; i++) {
printf("4");
}
for (int j = len / 2; j < len; j++) {
printf("7");
}
printf("\n");
}
int main() {
scanf("%s", str);
int len = strlen(str);
memset(flag, 0, sizeof(flag));
if (len % 2) {
print(len + 1);
} else {
if ((str[0] - '0') > 7) {
print(len + 2);
} else {
int cnt = 0, x = 0, y = 0;
for (int i = len - 1; i >= 0; i--) {
if ((str[i] - '0' + cnt) > 7) {
if (i == 0) {
print(len + 2);
return 0;
}
cnt = 1;
str[i] = '4';
} else if ((str[i] - '0' + cnt) > 4 && (str[i] - '0' + cnt) < 7) {
cnt = 0;
str[i] = '7';
flag[i + 1] = 1;
} else if ((str[i] - '0' + cnt) < 4) {
cnt = 0;
str[i] = '4';
flag[i + 1] = 1;
} else if ((str[i] - '0' + cnt) == 4) {
str[i] = '4';
if (cnt) {
flag[i + 1] = 1;
}
cnt = 0;
} else {
str[i] = '7';
if (cnt) {
flag[i + 1] = 1;
}
cnt = 0;
}
}
int pos = -1;
for (int i = 0; i < len; i++) {
if (flag[i]) {
pos = i;
break;
}
}
if (pos != -1)
for (int i = pos; i < len; i++) {
str[i] = '4';
}
for (int i = 0; i < len; i++) {
if (str[i] == '4')
x++;
else
y++;
}
if (x == y)
printf("%s\n", str);
else if (x > y) {
int ans = x - y, flag = 0;
for (int i = len - 1; i >= 0; i--) {
if (ans == 0) {
printf("%s\n", str);
break;
} else {
if (str[i] == '4') {
str[i] = '7';
ans -= 2;
}
}
}
} else {
int ans = y - x;
for (int i = len - 1; i >= 0; i--) {
int p = 0;
if ((str[i] - '0') == 4) {
for (int j = 0; j < i; j++) {
if (str[j] == '4') p++;
}
if (((len - 1 - i) + p) >= len / 2) {
str[i] = '7';
ans += 2;
for (int j = i + 1; j < len; j++) {
if (ans == 0) {
printf("%s\n", str);
return 0;
}
if (str[j] == '7') {
str[j] = '4';
ans -= 2;
}
}
printf("%s\n", str);
return 0;
}
}
}
print(len + 2);
}
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100105], out[100105];
int a, b;
int l;
void print(int n) {
int i;
for (i = 1; i <= n / 2; i++) printf("4");
for (i = 1; i <= n / 2; i++) printf("7");
cout << endl;
}
int solve(int p) {
if (p >= l) return 1;
int i, j, k;
int flag = 1;
if (s[p] > '7') {
return 0;
} else if (s[p] < '4') {
for (i = a; i < l / 2; i++) out[p++] = '4';
for (i = b; i < l / 2; i++) out[p++] = '7';
return 1;
} else if (s[p] > '4' && s[p] < '7') {
if (b >= l / 2) return 0;
out[p] = '7';
b++;
for (i = a; i < l / 2; i++) out[++p] = '4';
for (i = b; i < l / 2; i++) out[++p] = '7';
return 1;
} else if (s[p] == '4') {
if (a < l / 2) {
out[p] = '4';
a++;
if (solve(p + 1))
return 1;
else {
a--;
if (b >= l / 2) return 0;
out[p] = '7';
b++;
for (i = a; i < l / 2; i++) out[++p] = '4';
for (i = b; i < l / 2; i++) out[++p] = '7';
return 1;
}
} else {
out[p] = '7';
b++;
for (i = a; i < l / 2; i++) out[++p] = '4';
for (i = b; i < l / 2; i++) out[++p] = '7';
return 1;
}
} else if (s[p] == '7') {
if (b >= l / 2) return 0;
out[p] = '7';
b++;
if (solve(p + 1)) return 1;
b--;
return 0;
}
}
int main() {
int i, j, k;
while (cin >> s) {
l = strlen(s);
if (l % 2)
print(l + 1);
else {
a = 0, b = 0;
int tmp = solve(0);
if (!tmp)
print(l + 2);
else {
out[l] = '\0';
printf("%s\n", out);
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char n[100005];
char ans[100005];
int len;
bool dfs(int pos, int cnt4, int cnt7, bool toup) {
if (pos == len) return true;
if (toup) {
for (int i = 0; i < cnt4; i++) ans[pos++] = '4';
for (int i = 0; i < cnt7; i++) ans[pos++] = '7';
return true;
}
if (n[pos] <= '4' && cnt4) {
if (dfs(pos + 1, cnt4 - 1, cnt7, n[pos] < '4')) {
ans[pos] = '4';
return true;
}
}
if (n[pos] <= '7' && cnt7) {
if (dfs(pos + 1, cnt4, cnt7 - 1, n[pos] < '7')) {
ans[pos] = '7';
return true;
}
}
return false;
}
int main() {
while (cin >> n) {
len = strlen(n);
if (len % 2 || !dfs(0, len / 2, len / 2, false)) {
int x = (len % 2 ? (len + 1) / 2 : (len + 2) / 2);
for (int i = 1; i <= x; i++) cout << 4;
for (int i = 1; i <= x; i++) cout << 7;
cout << endl;
continue;
}
cout << ans << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char s[1000000];
int l, i, f[1100000];
bool bo;
void dfs(int a, int b, int c) {
if (bo) return;
if (c > l) {
for (i = 1; i <= l; i++) cout << f[i];
bo = true;
return;
}
if (bo) return;
if (int(s[c - 1]) - 48 < 4 && a) {
for (i = 1; i < c; i++) cout << f[i];
cout << "4";
for (i = 1; i < a; i++) cout << "4";
for (i = 1; i <= b; i++) cout << "7";
bo = true;
return;
}
if (bo) return;
if (int(s[c - 1]) - 48 == 4 && a) {
f[c] = 4;
dfs(a - 1, b, c + 1);
}
if (bo) return;
if (int(s[c - 1]) - 48 < 7 && b) {
for (i = 1; i < c; i++) cout << f[i];
cout << "7";
for (i = 1; i <= a; i++) cout << "4";
for (i = 1; i < b; i++) cout << "7";
bo = true;
return;
}
if (bo) return;
if (int(s[c - 1]) - 48 == 7 && b) {
f[c] = 7;
dfs(a, b - 1, c + 1);
}
if (bo) return;
}
int main() {
gets(s);
l = strlen(s);
if (l % 2 == 1) {
l++;
for (i = 1; i + i <= l; i++) cout << "4";
for (i = 1; i + i <= l; i++) cout << "7";
return 0;
}
bo = false;
dfs(l / 2, l / 2, 1);
if (bo) return 0;
for (i = 1; i + i <= l + 2; i++) cout << "4";
for (i = 1; i + i <= l + 2; i++) cout << "7";
}
|
#include <bits/stdc++.h>
using namespace std;
char str[100005];
int flag[100005];
void print(int len) {
for (int i = 0; i < len / 2; i++) {
printf("4");
}
for (int j = len / 2; j < len; j++) {
printf("7");
}
printf("\n");
}
int main() {
while (~scanf("%s", str)) {
int flag1 = 0;
int len = strlen(str);
memset(flag, 0, sizeof(flag));
if (len % 2) {
print(len + 1);
continue;
}
if ((str[0] - '0') > 7) {
print(len + 2);
continue;
}
int cnt = 0, x = 0, y = 0;
for (int i = len - 1; i >= 0; i--) {
if ((str[i] - '0' + cnt) > 7) {
if (i == 0) {
print(len + 2);
flag1 = 1;
break;
}
cnt = 1;
str[i] = '4';
} else if ((str[i] - '0' + cnt) > 4 && (str[i] - '0' + cnt) < 7) {
cnt = 0;
str[i] = '7';
flag[i + 1] = 1;
} else if ((str[i] - '0' + cnt) < 4) {
cnt = 0;
str[i] = '4';
flag[i + 1] = 1;
} else if ((str[i] - '0' + cnt) == 4) {
str[i] = '4';
if (cnt) {
flag[i + 1] = 1;
}
cnt = 0;
} else {
str[i] = '7';
if (cnt) {
flag[i + 1] = 1;
}
cnt = 0;
}
}
if (flag1) continue;
int pos = -1;
for (int i = 0; i < len; i++) {
if (flag[i]) {
pos = i;
break;
}
}
if (pos != -1)
for (int i = pos; i < len; i++) {
str[i] = '4';
}
for (int i = 0; i < len; i++) {
if (str[i] == '4')
x++;
else
y++;
}
if (x == y)
printf("%s\n", str);
else if (x > y) {
int ans = x - y;
for (int i = len - 1; i >= 0; i--) {
if (ans == 0) {
printf("%s\n", str);
break;
} else {
if (str[i] == '4') {
str[i] = '7';
ans -= 2;
}
}
}
} else {
int ans = y - x;
for (int i = len - 1; i >= 0; i--) {
int p = 0;
if ((str[i] - '0') == 4) {
for (int j = 0; j < i; j++) {
if (str[j] == '4') p++;
}
if (((len - 1 - i) + p) >= len / 2) {
str[i] = '7';
ans += 2;
for (int j = i + 1; j <= len; j++) {
if (ans == 0) {
printf("%s\n", str);
flag1 = 1;
break;
}
if (str[j] == '7') {
str[j] = '4';
ans -= 2;
}
}
}
}
if (flag1) break;
}
if (flag1) continue;
print(len + 2);
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
inline int D() {
int t;
scanf("%d", &t);
return t;
}
inline long long LLD() {
long long t;
scanf("%lld", &t);
return t;
}
bool super(long long n) {
int cnt4 = 0, cnt7 = 0;
while (n > 0) {
if (n % 10 == 4)
cnt4++;
else
cnt7++;
n /= 10;
}
return cnt4 == cnt7;
}
int main() {
vector<long long> v;
v.push_back(0);
int i = 0;
while (v[i] <= 1000000000) {
long long curr = v[i];
v.push_back(curr * 10 + 4);
v.push_back(curr * 10 + 7);
++i;
}
int x = D();
for (int z = 0; z < v.size(); z++) {
if (v[z] >= x && super(v[z])) {
cout << v[z];
return 0;
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
const int MX = (1 << 19);
string str;
void jd(int n) {
for (int j = 1; j <= n; j += 2) cout << '4';
for (int j = 1; j <= n; j += 2) cout << '7';
cout << endl;
}
int n;
bool check(int pos) {
int rf = n / 2, rs = n / 2;
for (int j = 0; j <= pos; j++) {
if (str[j] != '4' && str[j] != '7') return 0;
if (str[j] == '4') {
if (rf)
rf--;
else
return 0;
}
if (str[j] == '7') {
if (rs)
--rs;
else
return 0;
}
}
for (int j = pos + 1; j < n; j++) {
if (str[j] > '7') return 0;
if (str[j] < '7' && rs) return 1;
if (str[j] == '7') {
if (rs)
--rs;
else
return 0;
continue;
}
if (str[j] > '4') return 0;
if (str[j] < '4' && rf) return 1;
if (str[j] == '4') {
if (rf)
rf--;
else
return 0;
continue;
}
}
return 1;
}
int main() {
cin >> str;
int f = count(str.begin(), str.end(), '4');
int s = count(str.begin(), str.end(), '7');
if (s == f && s + f == str.size()) {
cout << str << endl;
return 0;
}
n = str.size();
if (n % 2) {
++n;
jd(n);
return 0;
}
int st = 0, en = n - 1, mid, best = -1;
while (st <= en) {
mid = (st + en) / 2;
if (check(mid)) {
best = mid;
st = mid + 1;
} else
en = mid - 1;
}
if (best == -1 && !check(-1)) {
jd(n + 2);
return 0;
}
int rf = n / 2, rs = n / 2;
for (int j = 0; j <= best; j++) {
if (str[j] == '4')
rf--;
else
rs--;
cout << str[j];
}
if (str[best + 1] < '4') {
cout << '4';
rf--;
} else {
cout << '7';
rs--;
}
while (rf--) cout << '4';
while (rs--) cout << '7';
}
|
#include <bits/stdc++.h>
using namespace std;
string s;
int len, bagi2;
int cnt4 = 0, cnt7 = 0;
const int N = 100005;
int ar[N];
bool masih = false;
void rek(int pos) {
if (cnt4 > bagi2 || cnt7 > bagi2) return;
if (pos == len) {
masih = true;
return;
}
if (s[pos] < '4') {
int k = pos;
for (int i = 0; i < bagi2 - cnt4; i++) {
ar[k] = 4;
k++;
}
for (int i = 0; i < bagi2 - cnt7; i++) {
ar[k] = 7;
k++;
}
masih = true;
return;
} else if (s[pos] == '4') {
if (cnt4 < bagi2) {
ar[pos] = 4;
cnt4++;
rek(pos + 1);
cnt4--;
}
if (!masih && cnt7 < bagi2) {
int k = pos;
ar[k] = 7;
k++;
cnt7++;
for (int i = 0; i < bagi2 - cnt4; i++) {
ar[k] = 4;
k++;
}
for (int i = 0; i < bagi2 - cnt7; i++) {
ar[k] = 7;
k++;
}
masih = true;
}
return;
} else if (s[pos] > '4' && s[pos] < '7') {
if (bagi2 - cnt7) {
int k = pos;
ar[k] = 7;
k++;
cnt7++;
for (int i = 0; i < bagi2 - cnt4; i++) {
ar[k] = 4;
k++;
}
for (int i = 0; i < bagi2 - cnt7; i++) {
ar[k] = 7;
k++;
}
masih = true;
}
return;
} else if (s[pos] == '7') {
if (cnt7 < bagi2) {
ar[pos] = 7;
cnt7++;
rek(pos + 1);
cnt7--;
}
return;
} else if (s[pos] > '7')
return;
}
int main() {
cin >> s;
len = s.length();
if (len & 1) {
for (int i = 0; i <= len >> 1; i++) printf("4");
for (int i = 0; i <= len >> 1; i++) printf("7");
puts("");
} else {
bagi2 = len / 2;
rek(0);
if (masih) {
for (int i = 0; i < len; i++) printf("%d", ar[i]);
puts("");
} else {
for (int i = 0; i <= len >> 1; i++) printf("4");
for (int i = 0; i <= len >> 1; i++) printf("7");
puts("");
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const long long MAXN = 1010, INF = 100000000000;
long long a[100], n, k, ans = INF;
void check() {
long long res = 0, p = 1, k1 = 0, k2 = 0;
for (int i = 0; i < k; i++) {
res = res * 10 + a[i];
k1 += (a[i] == 4);
k2 += (a[i] == 7);
}
if (k1 == k2 && res >= n && res < ans) ans = res;
}
void calc(int p) {
for (int i = 4; p < k && i <= 7; i += 3) {
a[p] = i;
if (p + 1 == k)
check();
else
calc(p + 1);
}
}
int main() {
cin >> n;
for (k = 1; k <= 10; k++) calc(0);
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
void err(istream_iterator<string> it) {}
template <typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
cerr << *it << " = " << a << endl;
err(++it, args...);
}
long long n, ans = -1;
void DFS(long long m, int c) {
if (m >= n) {
if (ans == -1 || ans > m)
if (c == 0) ans = m;
}
if (m >= 10 * n) return;
DFS(m * 10 + 7, c + 1);
DFS(m * 10 + 4, c - 1);
}
int main() {
cin >> n;
DFS(0, 0);
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
char s[100024], an[100024];
int len;
bool f() {
int k1, k2;
k1 = k2 = len / 2;
int i, j;
for (i = 0; i < len; i++) {
if (s[i] != '4' && s[i] != '7') break;
if (s[i] == '4') {
k1--;
if (k1 < 0) {
for (j = 0; j < i; j++) printf("%c", s[j]);
for (; j < len; j++) printf("7");
puts("");
return 1;
}
} else if (s[i] == '7') {
k2--;
if (k2 < 0) {
for (j = i - 1; j >= 0 && s[j] == '4'; j--)
;
while (j >= 0 && s[j] == '7') j--;
if (j < 0) return 0;
k1 = k2 = len / 2;
for (i = 0; i < j; i++) {
putchar(s[i]);
if (s[i] == '4')
k1--;
else
k2--;
}
k2--;
putchar('7');
while (k1 > 0) {
putchar('4');
k1--;
}
while (k2 > 0) {
putchar('7');
k2--;
}
puts("");
return 1;
}
}
}
if (i == len) {
puts(s);
return 1;
}
if (s[i] < '4') {
for (j = 0; j < i; j++) printf("%c", s[j]);
if (k1 > 0) {
putchar('4');
k1--;
} else {
putchar('7');
k2--;
}
while (k1 > 0) {
putchar('4');
k1--;
}
while (k2 > 0) {
putchar('7');
k2--;
}
puts("");
return 1;
}
if (s[i] < '7') {
if (k2 > 0) {
for (j = 0; j < i; j++) printf("%c", s[j]);
putchar('7');
k2--;
while (k1 > 0) {
putchar('4');
k1--;
}
while (k2 > 0) {
putchar('7');
k2--;
}
puts("");
return 1;
} else {
for (j = i - 1; j >= 0 && s[j] == '4'; j--)
;
while (j >= 0 && s[j] == '7') j--;
if (j < 0) return 0;
k1 = k2 = len / 2;
for (i = 0; i < j; i++) {
putchar(s[i]);
if (s[i] == '4')
k1--;
else if (s[i] == '7')
k2--;
}
printf("7");
k2--;
while (k1 > 0) {
putchar('4');
k1--;
}
while (k2 > 0) {
putchar('7');
k2--;
}
puts("");
return 1;
}
} else {
if (i == 0) return 0;
if (k2 == 0) {
for (j = i - 1; j >= 0 && s[j] == '4'; j--)
;
while (j >= 0 && s[j] == '7') j--;
if (j < 0) return 0;
k1 = k2 = len / 2;
for (i = 0; i < j; i++) {
printf("%c", s[i]);
if (s[i] == '4')
k1--;
else if (s[i] == '7')
k2--;
}
putchar('7');
k2--;
while (k1 > 0) {
putchar('4');
k1--;
}
while (k2 > 0) {
putchar('7');
k2--;
}
puts("");
return 1;
}
for (j = i - 1; j >= 0 && s[j] == '7'; j--)
;
if (j < 0)
return 0;
else {
k1 = k2 = len / 2;
for (i = 0; i < j; i++) {
printf("%c", s[i]);
if (s[i] == '4')
k1--;
else if (s[i] == '7')
k2--;
}
putchar('7');
k2--;
while (k1 > 0) {
putchar('4');
k1--;
}
while (k2 > 0) {
putchar('7');
k2--;
}
puts("");
return 1;
}
}
}
int main() {
int i;
scanf("%s", s);
len = strlen(s);
if (len % 2) {
int k = len / 2 + 1;
for (i = 0; i < k; i++) putchar('4');
for (i = 0; i < k; i++) putchar('7');
puts("");
} else {
if (!f()) {
int k = len / 2 + 1;
for (i = 0; i < k; i++) putchar('4');
for (i = 0; i < k; i++) putchar('7');
puts("");
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
const int Maxn = 100005;
int sum[Maxn];
int need;
string s, res;
void tryGet() {
if (s.length() % 2) {
need = s.length() + 1;
return;
}
for (int i = s.length() - 1; i >= 0; i--)
if (s[i] > '7')
sum[i] = -1;
else if (s[i] == '7')
if (sum[i + 1] == -1)
sum[i] = -1;
else
sum[i] = 1 + sum[i + 1];
else if (s[i] > '4')
sum[i] = 1;
else if (s[i] == '4')
if (sum[i + 1] == 0)
sum[i] = 0;
else
sum[i] = 1;
else
sum[i] = 0;
int left4 = s.length() / 2, left7 = s.length() / 2;
if (sum[0] == -1 || sum[0] > left7) {
need = s.length() + 2;
return;
}
for (int i = 0; i < s.length(); i++) {
if (left4 && (s[i] < '4' ||
s[i] == '4' && sum[i + 1] != -1 && sum[i + 1] <= left7)) {
left4--;
res += "4";
} else if (left7 && sum[i] != -1 && sum[i] <= left7) {
left7--;
res += "7";
} else {
need = s.length() + 2;
res = "";
return;
}
if (res[i] > s[i]) break;
}
while (left4--) res += "4";
while (left7--) res += "7";
}
int main() {
getline(cin, s);
tryGet();
if (res == "") {
for (int i = 0; i < need / 2; i++) res += "4";
for (int i = 0; i < need / 2; i++) res += "7";
}
cout << res << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
long long N;
int tam;
long long res;
cin >> N;
for (tam = 1;; tam++) {
for (res = 0LL; res < (1LL << tam); res++) {
long long w = 0LL;
int carg = 0;
for (long long i = 0LL, pot = 1LL; i < tam; i++, pot *= 10LL) {
if (res & (1LL << i)) {
carg++;
w += 7LL * pot;
} else {
carg--;
w += 4LL * pot;
}
}
if (carg == 0 && w >= N) {
cout << w << endl;
return 0;
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string inp;
string str(int a, char b) {
if (a < 0) {
cout << inp << endl;
exit(0);
}
return string(a, b);
}
bool av(string a) {
int c1 = 0, c2 = 0;
for (int i = 0; i < a.size(); i++) {
if (a[i] != '4' && a[i] != '7') return 0;
if (a[i] == '4')
c1++;
else
c2++;
}
return c1 == c2;
}
string first(int a) {
string res;
for (int i = 0; i < a / 2; i++) res += '4';
for (int i = 0; i < a / 2; i++) res += '7';
return res;
}
string last(int a) {
string res;
for (int i = 0; i < a / 2; i++) res += '7';
for (int i = 0; i < a / 2; i++) res += '4';
return res;
}
int main() {
ios::sync_with_stdio(false);
cin >> inp;
if (inp.size() % 2 == 1) {
cout << first(inp.size() + 1) << endl;
return 0;
}
if (inp > last(inp.size())) {
cout << first(inp.size() + 2) << endl;
return 0;
}
if (av(inp)) {
cout << inp << endl;
return 0;
}
int c1 = 0, c2 = 0;
int t = inp.size() / 2;
for (int i = 0; i < inp.size(); i++) {
if (inp[i] != '4' && inp[i] != '7') {
if (inp[i] < '4' && c1 < t) {
cout << inp.substr(0, i) + str(t - c1, '4') + str(t - c2, '7') << endl;
return 0;
}
if (inp[i] < '7' && c2 < t) {
cout << inp.substr(0, i) + '7' + str(t - c1, '4') + str(t - c2 - 1, '7')
<< endl;
return 0;
}
for (int j = i - 1; j >= 0; j--) {
if (inp[j] == '4') {
cout << inp.substr(0, j) + '7' + str(t - c1 + 1, '4') +
str(t - c2 - 1, '7')
<< endl;
return 0;
} else
c2--;
}
}
if (inp[i] == '4' && c1 == t) {
cout << inp.substr(0, i) + str(t - c2, '7') << endl;
return 0;
}
if (inp[i] == '7' && c2 == t) {
for (int j = i - 1; j >= 0; j--) {
if (inp[j] == '4' && c2 != t) {
cout << inp.substr(0, j) + '7' + str(t - c1 + 1, '4') +
str(t - c2 - 1, '7')
<< endl;
return 0;
} else if (inp[j] == '7')
c2--;
else if (inp[j] == '4')
c1--;
}
}
if (inp[i] == '4')
c1++;
else
c2++;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int l;
string s;
char ret[100005];
bool f;
bool isOk(const string& s) {
bool f = true;
for (int i = 0; i < l / 2; ++i) {
if (s[i] - '0' != 7) {
if (s[i] - '0' > 7)
return false;
else
return true;
}
}
for (int i = l / 2; i < l; ++i) {
if (s[i] - '0' != 4) {
if (s[i] - '0' > 4)
return false;
else
return true;
}
}
return true;
}
void dfs(int pos, int four, bool big) {
if (f || pos > l || four > l / 2 || pos - four > l / 2) {
return;
}
if (pos == l) {
ret[l] = '\0';
cout << ret << endl;
f = 1;
return;
}
if (big) {
for (int i = pos; i < l; ++i) {
if (four < l / 2) {
four++;
ret[i] = '4';
} else {
ret[i] = '7';
}
}
ret[l] = '\0';
cout << ret << endl;
f = 1;
return;
}
if (s[pos] <= '4') {
ret[pos] = '4';
dfs(pos + 1, four + 1, s[pos] < '4');
}
if (s[pos] <= '7') {
ret[pos] = '7';
dfs(pos + 1, four, s[pos] < '7');
}
}
int main() {
while (cin >> s) {
l = s.length();
f = 0;
if (l % 2 == 1) {
for (int i = 0; i < (l + 1) / 2; ++i) {
cout << 4;
}
for (int i = (l + 1) / 2; i < l + 1; ++i) {
cout << 7;
}
cout << endl;
} else {
if (isOk(s)) {
dfs(0, 0, false);
} else {
for (int i = 0; i < (l + 2) / 2; ++i) {
cout << 4;
}
for (int i = (l + 2) / 2; i < l + 2; ++i) {
cout << 7;
}
cout << endl;
}
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
long long n, ans = 1ll << 60;
void F(long long x, int cnt_4, int cnt_7) {
if (x >= n) {
if (cnt_4 == cnt_7) {
ans = min(ans, x);
}
}
if (x > n * 100) return;
F(x * 10 + 4, cnt_4 + 1, cnt_7);
F(x * 10 + 7, cnt_4, cnt_7 + 1);
}
int main() {
cin >> n;
F(0, 0, 0);
cout << ans;
return 0;
}
|
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