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#include <bits/stdc++.h>
long long in, result = std::numeric_limits<long long>::max();
void next(long long n, int fours, int sevens) {
if (fours + sevens <= 10) {
if (n >= in && fours == sevens && n < result) {
result = n;
} else {
next(n * 10 + 4, fours + 1, sevens);
next(n * 10 + 7, fours, sevens + 1);
}
}
}
int main(int argc, char** argv) {
std::ios_base::sync_with_stdio(0);
std::cin >> in;
next(0, 0, 0);
std::cout << static_cast<long long>(result) << std::endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 100024;
char ch[N];
int ans[N], c[N];
int newwpos;
bool found;
bool check(int Nn) {
for (int i = 1; i <= Nn; i++) {
int nownum = ch[i] - '0', nowmost = i <= Nn / 2 ? 7 : 4;
if (nownum == nowmost)
continue;
else if (nownum > nowmost)
return false;
else
return true;
}
return true;
}
int main() {
scanf("%s", ch + 1);
int n = strlen(ch + 1);
if (n % 2 == 1 || !check(n)) {
n += n % 2 ? 1 : 2;
for (int i = 1; i <= n; i++) cout << (i <= n / 2 ? 4 : 7);
return 0;
}
int bef = -1, newwpos = n;
for (int i = 1; i <= n; i++) {
int nownum = ch[i] - '0';
if (nownum == 7 || nownum == 4)
c[ans[i] = nownum]++, bef = (ans[i] == 4 && !found ? i : bef);
if (nownum < 7 && nownum != 4) {
ans[i] = nownum < 4 ? 4 : 7, c[ans[i]]++, newwpos = i,
bef = (ans[i] == 4 && found ? i : bef);
}
if (c[4] > n / 2) newwpos = i, ans[newwpos] = 7;
if (c[7] == n / 2) found = 1;
if (c[7] > n / 2 || nownum > 7) newwpos = bef, ans[newwpos] = 7;
if (newwpos != n) break;
}
c[4] = 0, c[7] = 0;
for (int i = 1; i <= newwpos; i++) {
cout << ans[i];
c[ans[i]]++;
}
for (int i = 1; i <= (n / 2) - c[4]; i++) cout << 4;
for (int i = 1; i <= (n / 2) - c[7]; i++) cout << 7;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int len;
string s;
int main() {
cin >> s;
len = (int)s.size();
if (len % 2 == 1) {
cout << string(len / 2 + 1, '4') << string(len / 2 + 1, '7') << endl;
return 0;
}
bool lucky = true;
int cnt40 = 0, cnt70 = 0;
for (int i = 0; i < (int)s.size(); i++) {
if (s[i] != '4' && s[i] != '7') {
lucky = false;
break;
} else if (s[i] == '4')
cnt40++;
else
cnt70++;
}
if (lucky && cnt40 == cnt70) {
cout << s << endl;
return 0;
}
bool flag = false, bad = false;
for (int i = 1; i <= len / 2; i++) {
if (s[i - 1] > '7') {
flag = true;
break;
} else if (s[i - 1] < '7') {
bad = true;
break;
}
}
if (!flag && !bad) {
for (int i = len / 2; i < (int)s.size(); i++) {
if (s[i] > '4') {
flag = true;
break;
} else if (s[i] < '4') {
bad = true;
break;
}
}
}
if (flag) {
cout << string(len / 2 + 1, '4') << string(len / 2 + 1, '7') << endl;
return 0;
}
int eq = 0, no = -1;
int eq4 = len / 2, eq7 = len / 2;
for (int i = 0; i < (int)s.size(); i++) {
if (eq == -1) break;
if (s[i] < '4') {
no = i;
eq = -1;
} else if (s[i] == '4') {
if (eq7 > 0) {
no = i;
}
if (eq4 > 0) {
eq4--;
} else {
eq = -1;
}
} else if (s[i] < '7') {
if (eq7 > 0) {
no = i;
}
eq = -1;
} else if (s[i] == '7') {
if (eq7 > 0) {
eq7--;
} else {
eq = -1;
}
} else if (s[i] > '7') {
eq = -1;
}
}
int res4 = len / 2, res7 = len / 2;
for (int i = 0; i < (int)s.size(); i++) {
if (i < no) {
cout << s[i];
(s[i] == '4') ? res4-- : res7--;
} else if (i == no) {
if (s[i] < '4' && res4) {
cout << '4';
res4--;
} else {
res7--;
cout << '7';
}
} else {
if (res4) {
cout << '4';
res4--;
} else {
cout << '7';
res7--;
}
}
}
cout << endl;
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;
int can = 0;
for (; seven - can != ((n).size()) / 2 - 1; --i) {
if (res[i] == '7') ++can;
}
while (res[i] == '7') --i;
res[i] = '7';
++i;
for (; i < ((res).size()); ++i) res[i] = '4';
seven = count((res).begin(), (res).end(), '7');
}
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;
int n, i, j, c4[100005], c7[100005], co[100005];
char s[1000005];
int main() {
gets(s);
n = strlen(s);
for (i = 0; i < n; i++) {
if (i > 0) {
c4[i] = c4[i - 1];
c7[i] = c7[i - 1];
co[i] = co[i - 1];
}
if (s[i] == '4')
c4[i]++;
else if (s[i] == '7')
c7[i]++;
else
co[i]++;
}
if (n % 2 == 0 && co[n - 1] == 0 && c4[n - 1] == c7[n - 1]) {
puts(s);
exit(0);
}
if (n % 2 == 0)
for (i = n - 1; i >= 0; i--)
if (i == 0 || co[i - 1] == 0) {
for (j = (s[i] - '0') + 1; j < 10; j++)
if (j == 4 || j == 7) {
int n4 = (i == 0) ? 0 : c4[i - 1];
int n7 = (i == 0) ? 0 : c7[i - 1];
if (j == 4)
n4++;
else
n7++;
int o = n - 1 - i;
if (n4 + o >= n7 && n7 + o >= n4) {
s[i] = j + '0';
for (j = i + 1; j < n; j++) {
s[j] = '4';
n4++;
o--;
if (n7 + o < n4) {
s[j] = '7';
n4--;
n7++;
}
}
puts(s);
exit(0);
}
}
}
n++;
if (n % 2 == 1) n++;
for (i = 0; i < n; i++)
if (i < n / 2)
s[i] = '4';
else
s[i] = '7';
puts(s);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long int ans = 10e12, n;
void rc(long long int s, int i, int k1, int k2) {
if (k1 == k2 && s >= n) {
ans = min(ans, s);
return;
}
if (i > 10) return;
rc(s * 10 + 4, i + 1, k1 + 1, k2);
rc(s * 10 + 7, i + 1, k1, k2 + 1);
}
int main() {
cin >> n;
rc(0, 1, 0, 0);
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};
string s, t, ans;
void dfs(int i, int x, int y, bool g) {
if (x > s.size() / 2 || y > s.size() / 2) return;
if (i == s.size()) {
ans = t;
return;
}
if (g) {
t[i] = '4';
dfs(i + 1, x + 1, y, 1);
if (!(ans == "")) {
return;
}
t[i] = '7';
dfs(i + 1, x, y + 1, 1);
} else {
if (s[i] <= '4') {
t[i] = '4';
dfs(i + 1, x + 1, y, '4' > s[i]);
if (!(ans == "")) return;
}
if (s[i] <= '7') {
t[i] = '7';
dfs(i + 1, x, y + 1, '7' > s[i]);
if (!(ans == "")) return;
}
}
}
int main() {
cin >> s;
for (long long i = 0; i < (s.size() / 2); i++) {
t += '7';
}
for (long long i = 0; i < (s.size() / 2); i++) {
t += '4';
}
if (s.size() % 2 == 1 || s > t) {
for (long long i = 0; i < (s.size() / 2 + 1); i++) {
ans += '4';
}
for (long long i = 0; i < (s.size() / 2 + 1); i++) {
ans += '7';
}
cout << ans;
return 0;
}
t = s;
dfs(0, 0, 0, 0);
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s, ans, ans2;
int n;
void dfs(int i, int cnt4, int cnt7, bool big) {
if (cnt4 > n / 2 || cnt7 > n / 2) return;
if (i == n) {
ans2 = ans;
return;
}
if (big) {
ans[i] = '4';
dfs(i + 1, cnt4 + 1, cnt7, 1);
if (ans2 != "") return;
ans[i] = '7';
dfs(i + 1, cnt4, cnt7 + 1, 1);
} else {
if (s[i] <= '4') {
ans[i] = '4';
dfs(i + 1, cnt4 + 1, cnt7, s[i] < '4');
if (ans2 != "") return;
}
if (s[i] <= '7') {
ans[i] = '7';
dfs(i + 1, cnt4, cnt7 + 1, s[i] < '7');
}
}
}
int main() {
cin >> s;
n = s.size();
for (int i = 0; i < n / 2; i++) ans += '7';
for (int i = 0; i < n / 2; i++) ans += '4';
if (n % 2 || ans < s) {
for (int i = 0; i < n / 2 + 1; i++) cout << 4;
for (int i = 0; i < n / 2 + 1; i++) cout << 7;
return 0;
}
ans = s;
dfs(0, 0, 0, 0);
cout << ans2;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
bool issup(long long int a) {
int f = 0, s = 0;
while (a != 0) {
if (a % 10 == 4)
f++;
else
s++;
a /= 10;
}
if (f == s) return true;
return false;
}
int main() {
long long int n;
cin >> n;
queue<long long int> q;
q.push(4);
q.push(7);
vector<long long int> v;
long long int lim = 10000000000000LL;
while (!q.empty()) {
long long int x = q.front();
q.pop();
if (x > lim) break;
if (issup(x)) {
v.push_back(x);
}
q.push(x * 10 + 4);
q.push(x * 10 + 7);
}
v.pop_back();
sort(v.begin(), v.end());
cout << *lower_bound(v.begin(), v.end(), n);
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = int(3e5), mod = int(1e9) + 7;
char second[N];
int n;
int a[N], b[N];
int main() {
scanf("%s", second + 1);
n = strlen(second + 1);
int ok = 1;
for (int i = 1; i <= n; i++) {
if (second[i] != '7') {
if (second[i] > '7') ok = 0;
break;
}
}
if (n % 2 == 0) {
for (int i = 1; i <= n / 2; i++) {
if (second[i] != '7') {
if (second[i] > '7')
ok = 0;
else
ok = 2;
break;
}
}
if (ok == 1) {
for (int i = n / 2 + 1; i <= n; i++) {
if (second[i] != '4') {
if (second[i] > '4')
ok = 0;
else
ok = 2;
break;
}
}
}
}
if ((n & 1) || !ok) {
int len = n / 2 + 1;
for (int i = 1; i <= len; i++) {
printf("4");
}
for (int i = 1; i <= len; i++) {
printf("7");
}
return 0;
}
for (int i = 1; i <= n; i++) {
a[i] = a[i - 1];
b[i] = b[i - 1];
if (second[i] == '4') a[i]++;
if (second[i] == '7') b[i]++;
}
if (a[n] == n / 2 && b[n] == n / 2) {
printf("%s", second + 1);
return 0;
}
int mx = -1, cur = 0;
int c4 = 0, c7 = 0;
for (int i = 1; i <= n; i++) {
int n4 = a[i - 1];
int n7 = b[i - 1];
if (n4 + n7 != i - 1) break;
bool ok = 1;
if (second[i] < '4') {
n4++;
if (n4 <= n / 2 && n7 <= n / 2) {
mx = i - 1;
cur = 4;
c4 = n4;
c7 = n7;
ok = 0;
}
}
if (ok && second[i] < '7') {
n7++;
if (n4 <= n / 2 && n7 <= n / 2) {
mx = i - 1;
cur = 7;
c4 = n4;
c7 = n7;
}
}
}
for (int i = 1; i <= mx; i++) printf("%c", second[i]);
printf("%d", cur);
while (c4 < n / 2) {
printf("4");
c4++;
}
while (c7 < n / 2) {
printf("7");
c7++;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int n;
string s, t, a;
void dfs(int i, int c4, int c7, bool d) {
if (c4 + n - i < n / 2 || c7 + n - i < n / 2) return;
if (i == n) {
a = t;
return;
}
if (d) {
t[i] = '4';
dfs(i + 1, c4 + 1, c7, 1);
if (a != "") return;
t[i] = '7';
dfs(i + 1, c4, c7 + 1, 1);
} else {
if (s[i] <= '4') {
t[i] = '4';
dfs(i + 1, c4 + 1, c7, s[i] < '4');
if (a != "") return;
}
if (s[i] <= '7') {
t[i] = '7';
dfs(i + 1, c4, c7 + 1, s[i] < '7');
}
}
}
int main() {
cin >> s;
restart:
if (s.size() % 2) s = "0" + s;
n = s.size();
t = string(n, '0');
dfs(0, 0, 0, 0);
if (a == "") {
s = "00" + s;
goto restart;
} else {
cout << a << endl;
}
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
int n, count = 0, q = 0;
long long ans = 9999999999999;
cin >> n;
q = n;
while (q) {
q /= 10;
count++;
}
if (count & 1) {
for (int i = 0; i < count / 2 + 1; i++) cout << '4';
for (int i = 0; i < count / 2 + 1; i++) cout << '7';
return 0;
}
for (int i = 0; i < (1 << (count + 3)); i++) {
long long res = 0, q4 = 0, q7 = 0;
for (int j = 0; j < count + 2; j++) {
if ((1 << j) > i && res >= n) break;
res *= 10;
if (i & (1 << j)) {
res += 4;
q4++;
} else {
res += 7;
q7++;
}
}
if (q4 == q7 && res >= n && res < ans) ans = res;
}
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string ans, s;
long long int ok, l;
void fill(long long int pos, long long int ctr4, long long int ctr7) {
for (long long int i = 0; i < ctr4; i++) ans[pos + i] = '4';
for (long long int i = 0; i < ctr7; i++) ans[pos + i + ctr4] = '7';
ok = 1;
}
void solve(long long int pos, long long int ctr4, long long int ctr7) {
if (pos == l) {
ok = 1;
return;
}
long long int cur = s[pos] - '0';
if (cur < 4) {
fill(pos, ctr4, ctr7);
return;
}
if (cur == 4 && ctr4) {
ans[pos] = '4';
solve(pos + 1, ctr4 - 1, ctr7);
if (ok) return;
}
if (cur < 7 && ctr7) {
ans[pos] = '7';
fill(pos + 1, ctr4, ctr7 - 1);
return;
}
if (cur == 7 && ctr7) {
ans[pos] = '7';
solve(pos + 1, ctr4, ctr7 - 1);
}
}
int main() {
long long int i, j;
cin >> s;
ans = s;
l = s.length();
ok = 0;
if (l % 2 == 0) solve(0, l / 2, l / 2);
if (!ok) {
l++;
for (i = 0; i < (l + 1) / 2; i++) cout << "4";
for (i = 0; i < (l + 1) / 2; i++) cout << "7";
return 0;
}
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
char s[100010];
int main() {
int i, j, k, l, m, n, p, q, y, z;
scanf("%s", s);
m = strlen(s);
if (m % 2 == 1) {
for (i = 0; i < (m + 1) / 2; i++) printf("4");
for (i = 0; i < (m + 1) / 2; i++) printf("7");
printf("\n");
return 0;
}
if (s[0] == '1' || s[0] == '2' || s[0] == '3') {
for (i = 0; i < m / 2; i++) printf("4");
for (i = 0; i < m / 2; i++) printf("7");
printf("\n");
return 0;
}
if (s[0] == '8' || s[0] == '9') {
for (i = 0; i <= m / 2; i++) printf("4");
for (i = 0; i <= m / 2; i++) printf("7");
printf("\n");
return 0;
}
if (s[0] == '5' || s[0] == '6') {
printf("7");
for (i = 0; i < m / 2; i++) printf("4");
for (i = 0; i < m / 2 - 1; i++) printf("7");
printf("\n");
return 0;
}
if (s[0] == '4') {
j = 0;
k = 0;
l = 0, p = 0, q = 0;
for (i = 0; i < m; i++) {
if (s[i] == '4')
k++;
else if (s[i] == '7')
l++;
else if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3') {
j = 1;
p = i;
break;
} else if (s[i] == '5' || s[i] == '6') {
j = 2;
p = i;
break;
} else {
j = 3;
p = i;
break;
}
if (k == m / 2 || l == m / 2) {
p = i;
break;
}
}
if (j == 1) {
for (i = 0; i < p; i++) printf("%c", s[i]);
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l; i++) printf("7");
printf("\n");
return 0;
} else if (j == 2) {
for (i = 0; i < p; i++) printf("%c", s[i]);
printf("7");
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l - 1; i++) printf("7");
printf("\n");
return 0;
} else if (j == 3) {
if (k == 1) {
printf("7");
for (i = 0; i < m / 2; i++) printf("4");
for (i = 0; i < m / 2 - 1; i++) printf("7");
printf("\n");
return 0;
} else {
for (z = p - 1; z; z--)
if (s[z] == '4') break;
k = 0;
l = 0;
for (i = 0; i < z; i++) {
if (s[i] == '4') k++;
if (s[i] == '7') l++;
printf("%c", s[i]);
}
printf("7");
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l - 1; i++) printf("7");
printf("\n");
return 0;
}
} else {
if (k == m / 2) {
y = 0;
for (i = p + 1; i < m; i++) {
if (s[i] < '7') break;
if (s[i] > '7') {
y = 1;
break;
}
}
if (y == 0) {
for (i = 0; i <= p; i++) printf("%c", s[i]);
for (i = p + 1; i < m; i++) printf("7");
printf("\n");
return 0;
} else {
for (i = 0; i < p; i++) printf("%c", s[i]);
printf("7");
printf("4");
for (i = p + 2; i < m; i++) printf("7");
printf("\n");
return 0;
}
} else {
y = 0;
for (i = p + 1; i < m; i++) {
if (s[i] < '4') break;
if (s[i] > '4') {
y = 1;
break;
}
}
if (y == 0) {
for (i = 0; i <= p; i++) printf("%c", s[i]);
for (i = p + 1; i < m; i++) printf("4");
printf("\n");
return 0;
} else {
if (k == 1) {
printf("7");
for (i = 0; i < m / 2; i++) printf("4");
for (i = 0; i < m / 2 - 1; i++) printf("7");
printf("\n");
return 0;
} else {
for (z = p - 1; z; z--)
if (s[z] == '4') break;
k = 0, l = 0;
for (i = 0; i < z; i++) {
if (s[i] == '4') k++;
if (s[i] == '7') l++;
printf("%c", s[i]);
}
printf("7");
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l - 1; i++) printf("7");
printf("\n");
return 0;
}
}
}
}
} else {
j = 0;
k = 0;
l = 0, p = 0, q = 0;
for (i = 0; i < m; i++) {
if (s[i] == '4')
k++;
else if (s[i] == '7')
l++;
else if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3') {
j = 1;
p = i;
break;
} else if (s[i] == '5' || s[i] == '6') {
j = 2;
p = i;
break;
} else {
j = 3;
p = i;
break;
}
if (k == m / 2 || l == m / 2) {
p = i;
break;
}
}
if (j == 1) {
for (i = 0; i < p; i++) printf("%c", s[i]);
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l; i++) printf("7");
printf("\n");
return 0;
} else if (j == 2) {
for (i = 0; i < p; i++) printf("%c", s[i]);
printf("7");
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l - 1; i++) printf("7");
printf("\n");
return 0;
} else if (j == 3) {
if (k == 0) {
for (i = 0; i <= m / 2; i++) printf("4");
for (i = 0; i <= m / 2; i++) printf("7");
printf("\n");
return 0;
} else {
for (z = p - 1; z; z--)
if (s[z] == '4') break;
k = 0;
l = 0;
for (i = 0; i < z; i++) {
if (s[i] == '4') k++;
if (s[i] == '7') l++;
printf("%c", s[i]);
}
printf("7");
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l - 1; i++) printf("7");
printf("\n");
return 0;
}
} else {
if (k == m / 2) {
y = 0;
for (i = p + 1; i < m; i++) {
if (s[i] < '7') break;
if (s[i] > '7') {
y = 1;
break;
}
}
if (y == 0) {
for (i = 0; i <= p; i++) printf("%c", s[i]);
for (i = p + 1; i < m; i++) printf("7");
printf("\n");
return 0;
} else {
for (i = 0; i < p; i++) printf("%c", s[i]);
printf("7");
printf("4");
for (i = p + 2; i < m; i++) printf("7");
printf("\n");
return 0;
}
} else {
y = 0;
for (i = p + 1; i < m; i++) {
if (s[i] < '4') break;
if (s[i] > '4') {
y = 1;
break;
}
}
if (y == 0) {
for (i = 0; i <= p; i++) printf("%c", s[i]);
for (i = p + 1; i < m; i++) printf("4");
printf("\n");
return 0;
} else {
if (k == 0) {
for (i = 0; i <= m / 2; i++) printf("4");
for (i = 0; i <= m / 2; i++) printf("7");
printf("\n");
return 0;
} else {
for (z = p - 1; z; z--)
if (s[z] == '4') break;
k = 0, l = 0;
for (i = 0; i < z; i++) {
if (s[i] == '4') k++;
if (s[i] == '7') l++;
printf("%c", s[i]);
}
printf("7");
for (i = 0; i < m / 2 - k; i++) printf("4");
for (i = 0; i < m / 2 - l - 1; i++) printf("7");
printf("\n");
return 0;
}
}
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string build(int x, int y) {
string ans;
for (int n_ = (x), i = 0; i < n_; ++i) ans += '4';
for (int n_ = (y), i = 0; i < n_; ++i) ans += '7';
return ans;
}
string solve(string number) {
string ans;
if (((int)(number).size()) % 2 == 1) {
int sz = ((int)(number).size()) + 1;
return build(sz / 2, sz / 2);
} else {
int cnt4 = count((number).begin(), (number).end(), '4');
int cnt7 = count((number).begin(), (number).end(), '7');
if (cnt4 == cnt7 && cnt4 + cnt7 == ((int)(number).size())) {
return number;
}
int should_change = ((int)(number).size()) - 1;
for (int n_ = (((int)(number).size())), i = 0; i < n_; ++i) {
if (number[i] != '4' && number[i] != '7') {
should_change = i;
break;
}
}
cnt4 = cnt7 = 0;
for (int n_ = (should_change + 1), i = 0; i < n_; ++i) {
if (number[i] == '4') cnt4++;
if (number[i] == '7') cnt7++;
}
int sz = number.size() / 2;
for (int i = should_change; i >= 0; --i) {
if (number[i] == '4') cnt4--;
if (number[i] == '7') cnt7--;
if ('4' > number[i]) {
if (cnt4 + 1 <= sz && cnt7 <= sz) {
return number.substr(0, i) + "4" + build(sz - cnt4 - 1, sz - cnt7);
}
}
if ('7' > number[i]) {
if (cnt4 <= sz && cnt7 + 1 <= sz) {
return number.substr(0, i) + "7" + build(sz - cnt4, sz - cnt7 - 1);
}
}
}
int n = sz * 2 + 2;
return build(n / 2, n / 2);
}
}
int main() {
string number;
while (cin >> number) {
cout << solve(number) << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
struct num {
long long x;
long long c4;
long long c7;
};
void solve() {
queue<struct num> q;
q.push({0, 0, 0});
vector<long long> v;
while (!q.empty()) {
long long x = q.front().x;
long long c = q.front().c4;
long long c1 = q.front().c7;
if (c == c1) v.push_back(x);
q.pop();
if (x > 1e10) break;
q.push({10 * x + 4, c + 1, c1});
q.push({10 * x + 7, c, c1 + 1});
}
long long n;
cin >> n;
cout << v[lower_bound(v.begin(), v.end(), n) - v.begin()] << "\n";
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
solve();
}
|
#include <bits/stdc++.h>
using namespace std;
int len;
string a, b, c;
int main() {
while (cin >> a) {
b.clear();
c.clear();
len = a.size();
int i;
if (len & 1) {
len++;
for (i = 0; i < len / 2; i++) b += '4';
for (i = len / 2; i < len; i++) b += '7';
} else {
for (i = 0; i < len / 2; i++) c += '7';
for (i = len / 2; i < len; i++) c += '4';
if (a == c)
b = c;
else if (a > c) {
len = len + 2;
for (i = 0; i < len / 2; i++) b += '4';
for (i = len / 2; i < len; i++) b += '7';
} else {
int x4 = len / 2, y7 = len / 2;
bool jie = false;
for (i = 0; !jie && i < len; i++) {
if (a[i] <= '4' && x4 - 1 >= 0) {
b += '4';
x4--;
if (a[i] < '4') {
jie = true;
break;
}
} else if (a[i] <= '7' && y7 - 1 >= 0) {
b += '7';
y7--;
if (a[i] < '7') {
jie = true;
break;
}
} else {
while (*(b.end() - 1) == '7') {
b.erase(b.end() - 1);
y7++;
}
if (*(b.end() - 1) == '4') {
b.erase(b.end() - 1);
x4++;
}
if (y7 - 1 >= 0) {
b += '7';
y7--;
jie = true;
break;
}
}
}
if (jie) {
while (x4 - 1 >= 0) {
b += '4';
x4--;
}
while (y7 - 1 >= 0) {
b += '7';
y7--;
}
}
}
}
cout << b << endl;
a.clear();
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
long long int tt = 1;
for (long long int t = 1; t <= tt; t++) {
string s;
cin >> s;
long long int n = s.size();
if (n % 2 == 0) {
string r = "";
for (long long int i = 1; i <= n; i++) {
r += (i <= n / 2) ? '7' : '4';
}
if (s > r) {
reverse(r.begin(), r.end());
cout << "4" << r << "7";
} else {
long long int four = n / 2, seven = n / 2;
bool flag = 0;
r = "";
for (long long int i = 0; i <= n - 1; i++) {
if (s[i] < '4') {
break;
} else if (s[i] == '4') {
if (four == 0) {
break;
}
r += '4';
four--;
} else if (s[i] < '7') {
if (seven > 0) {
r += '7';
seven--;
} else {
flag = 1;
}
break;
} else if (s[i] == '7') {
if (seven == 0) {
flag = 1;
break;
}
r += '7';
seven--;
} else {
flag = 1;
break;
}
}
if (flag) {
long long int i = r.size(), index;
for (long long int j = i - 1; j >= 0; j--) {
if (s[j] == '4') {
if (seven > 0) {
index = j;
break;
}
} else {
seven++;
}
}
r = "";
four = seven = n / 2;
for (long long int j = 0; j <= index - 1; j++) {
r += s[j];
(s[j] == '4') ? four-- : seven--;
}
r += '7';
seven--;
}
while (four--) {
r += '4';
}
while (seven--) {
r += '7';
}
cout << r;
}
} else {
for (long long int i = 1; i <= n / 2 + 1; i++) {
cout << "4";
}
for (long long int i = 1; i <= n / 2 + 1; i++) {
cout << "7";
}
}
cout << '\n';
}
return 0;
}
|
#include <bits/stdc++.h>
const int M = 1e5 + 7;
const long long N = 2e9 + 9;
using namespace std;
int n;
queue<pair<long long, int> > q;
int main() {
scanf("%d", &n);
q.push(make_pair(0, 0));
while (1) {
long long x = q.front().first;
int y = q.front().second;
q.push(make_pair(x * 10 + 4, y + 1));
if (q.back().first >= n && q.back().second == 0) {
cout << q.back().first;
return 0;
}
q.push(make_pair(x * 10 + 7, y - 1));
if (q.back().first >= n && q.back().second == 0) {
cout << q.back().first;
return 0;
}
q.pop();
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
const int Mod = 1000000007;
const int INF = 0x3f3f3f3f;
const long long LL_INF = 0x3f3f3f3f3f3f3f3f;
const double e = exp(1);
const double PI = acos(-1);
const double ERR = 1e-10;
char str[maxn];
char ans[maxn];
int len, n;
int dfs(int pos, int num4, int num7) {
if (pos == n && num4 == 0 && num7 == 0) return 1;
if (n - pos < abs(num4 - num7)) return 0;
if (str[pos] > '7') return 0;
if (str[pos] < '4') {
if (num4) {
ans[pos] = 4;
pos++;
num4--;
for (int i = pos; i < pos + num4; i++) ans[i] = 4;
for (int i = pos + num4; i < n; i++) ans[i] = 7;
return 1;
} else {
ans[pos] = 7;
pos++;
num7--;
for (int i = pos; i < pos + num4; i++) ans[i] = 4;
for (int i = pos + num4; i < n; i++) ans[i] = 7;
return 1;
}
}
if (str[pos] == '4') {
if (num4) {
ans[pos] = 4;
if (dfs(pos + 1, num4 - 1, num7)) return 1;
}
if (num7) {
ans[pos] = 7;
pos++;
for (int i = pos; i < pos + num4; i++) ans[i] = 4;
for (int i = pos + num4; i < n; i++) ans[i] = 7;
return 1;
}
}
if (str[pos] > '4' && str[pos] < '7' && num7) {
ans[pos] = 7;
pos++;
for (int i = pos; i < pos + num4; i++) ans[i] = 4;
for (int i = pos + num4; i < n; i++) ans[i] = 7;
return 1;
}
if (str[pos] == '7' && num7) {
ans[pos] = 7;
return dfs(pos + 1, num4, num7 - 1);
}
return 0;
}
int main() {
scanf("%s", str);
len = strlen(str);
n = len;
if (len % 2 == 1) {
len++;
for (int i = 0; i < len / 2; i++) printf("4");
for (int i = len / 2; i < len; i++) printf("7");
} else {
if (dfs(0, len / 2, len / 2)) {
for (int i = 0; i < n; i++) {
printf("%d", ans[i]);
}
} else {
len += 2;
for (int i = 0; i < len / 2; i++) printf("4");
for (int i = len / 2; i < len; i++) printf("7");
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string getNextLucky(string s) {
int n = s.size();
if (s[0] > '7') {
string ret = "";
for (int i = 0; i <= n; i++) {
ret += '4';
}
return ret;
}
bool flg = false;
for (int i = 0; i < n; i++) {
if (s[i] == '4' || s[i] == '7') continue;
if (s[i] > '7') {
for (int j = i; j < n; j++) {
s[j] = '7';
}
flg = true;
break;
} else if (s[i] < '4') {
for (int j = i; j < n; j++) {
s[j] = '4';
}
return s;
exit(0);
} else if (s[i] < '7') {
for (int j = i + 1; j < n; j++) {
s[j] = '4';
}
s[i] = '7';
return s;
exit(0);
}
}
if (!flg) return s;
reverse(s.begin(), s.end());
int carry = 1;
for (int i = 0; i < n; i++) {
if (s[i] == '4') {
s[i] = '7';
carry = 0;
break;
} else {
s[i] = '4';
}
}
if (carry) s += '4';
reverse(s.begin(), s.end());
return s;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
cout << setprecision(32);
string s;
cin >> s;
s = getNextLucky(s);
int n = s.size();
if (n & 1) {
int k = (n + 1) / 2;
for (int i = 0; i < k; i++) {
cout << 4;
}
for (int i = 0; i < k; i++) {
cout << 7;
}
} else {
int k = n / 2;
int cnt4 = 0, cnt7 = 0;
for (int i = 0; i < n; i++) {
if (s[i] == '4')
cnt4++;
else
cnt7++;
}
if (cnt4 == cnt7) {
cout << s << endl;
exit(0);
}
if (cnt4 > cnt7) {
int req = (cnt4 - cnt7) / 2;
for (int i = n - 1; i >= 0; i--) {
if (s[i] == '4') {
s[i] = '7';
req--;
}
if (req == 0) break;
}
cout << s << endl;
exit(0);
}
if (cnt4 == 0) {
for (int i = 0; i <= k; i++) {
cout << 4;
}
for (int i = 0; i <= k; i++) {
cout << 7;
}
exit(0);
}
if (cnt7 > cnt4) {
for (int i = n - 1; i >= 0; i--) {
if (s[i] == '4') cnt4--;
if (s[i] == '7') cnt7--;
if (s[i] == '4') {
int t7 = cnt7 + 1;
int t4 = cnt4 + (n - i - 1);
if (t4 >= t7) {
for (int j = i + 1; j < n; j++) {
s[j] = '4';
}
s[i] = '7';
break;
}
}
}
}
cnt4 = cnt7 = 0;
for (int i = 0; i < n; i++) {
if (s[i] == '4')
cnt4++;
else
cnt7++;
}
if (cnt4 == cnt7) {
cout << s << endl;
exit(0);
}
if (cnt4 > cnt7) {
int req = (cnt4 - cnt7) / 2;
for (int i = n - 1; i >= 0; i--) {
if (s[i] == '4') {
s[i] = '7';
req--;
}
if (req == 0) break;
}
cout << s << endl;
exit(0);
}
for (int i = 0; i <= k; i++) {
cout << 4;
}
for (int i = 0; i <= k; i++) {
cout << 7;
}
exit(0);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
struct _ {
_() { ios_base::sync_with_stdio(0); }
} _;
template <class A, class B>
ostream &operator<<(ostream &o, pair<A, B> t) {
o << "(" << t.first << ", " << t.second << ")";
return o;
}
template <class T>
void PV(T a, T b, int n = 0) {
int c = 0;
while (a < b) {
cout << *a++;
if (a < b && (n == 0 || ++c % n))
cout << " ";
else
cout << endl;
}
}
template <class T>
inline bool chmin(T &a, T b) {
return a > b ? a = b, 1 : 0;
}
template <class T>
inline bool chmax(T &a, T b) {
return a < b ? a = b, 1 : 0;
}
template <class T>
string tostring(T first, int len = 0) {
stringstream ss;
ss << first;
string r = ss.str();
if (r.length() < len) r = string(len - r.length(), '0') + r;
return r;
}
template <class T>
void convert(string first, T &r) {
stringstream ss(first);
ss >> r;
}
const long long linf = 0x3f3f3f3f3f3f3f3fLL;
const int inf = 0x3f3f3f3f;
const int mod = int(1e9) + 7;
const int N = 111111;
vector<int> n;
int m;
vector<string> vs;
int path[N];
bool dfs(int n4, int n7, int e) {
if (n4 > n.size() / 2 || n7 > n.size() / 2) return 0;
if (n4 + n7 == n.size()) {
if (n4 != n7) {
return 0;
} else {
if (n4 == n7) {
string s;
for (int i = 0; i < n4 + n7; i++) s += path[i] + '0';
vs.push_back(s);
return 1;
}
}
}
if (e == 0) {
int rn4 = n.size() / 2 - n4;
int rn7 = n.size() / 2 - n7;
string s;
for (int i = 0; i < n4 + n7; i++) s += path[i] + '0';
s += string(rn4, '4') + string(rn7, '7');
vs.push_back(s);
return 1;
} else {
if (n[n4 + n7] > 7) {
return 0;
} else if (n[n4 + n7] > 4) {
path[n4 + n7] = 7;
if (dfs(n4, n7 + 1, n[n4 + n7] == 7)) return 1;
} else {
path[n4 + n7] = 4;
if (dfs(n4 + 1, n7, n[n4 + n7] == 4)) return 1;
path[n4 + n7] = 7;
if (dfs(n4, n7 + 1, n[n4 + n7] == 7)) return 1;
}
}
return 0;
}
int main() {
string s;
cin >> s;
for (auto i : s) n.push_back(i - '0');
if (n.size() % 2 == 0) dfs(0, 0, 1);
reverse((n).begin(), (n).end());
n.push_back(0);
reverse((n).begin(), (n).end());
if (n.size() % 2 == 0) dfs(0, 0, 1);
reverse((n).begin(), (n).end());
n.push_back(0);
reverse((n).begin(), (n).end());
if (n.size() % 2 == 0) dfs(0, 0, 1);
string best = vs[0];
for (int i = 1; i < vs.size(); i++) {
if (best.length() > vs[i].length())
best = vs[i];
else if (best.length() == vs[i].length())
chmin(best, vs[i]);
}
cout << best << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int maxlen = 200000;
char s[maxlen];
int len;
vector<int> v;
vector<int> res;
inline void print(vector<int> &tt) {
for (int i = 0; i < (int)tt.size(); i++) {
cout << tt[i];
}
}
inline bool lss(vector<int> &a, vector<int> &b) {
for (int i = 0; i < (int)a.size(); i++) {
if (a[i] != b[i]) return a[i] < b[i];
}
return false;
}
int main() {
scanf("%s", s);
len = strlen(s);
v.resize(len);
for (int i = 0; i < len; i++) {
v[i] = s[i] - '0';
}
int ct4 = 0, ct7 = 0;
for (int i = 0; i < len; i++) {
ct4 += (v[i] == 4);
ct7 += (v[i] == 7);
}
if (ct4 + ct7 == len && ct4 == ct7) {
print(v);
return 0;
} else {
if (v.size() % 2 == 1) {
len = v.size() + 1;
for (int i = 1; i <= len; i++) {
if (i <= len / 2)
cout << 4;
else
cout << 7;
}
return 0;
}
vector<int> mx(v.size()), mn(v.size());
for (int i = 1; i <= (int)v.size(); i++) {
if (i <= len / 2) {
mn[i - 1] = 4;
mx[i - 1] = 7;
} else {
mn[i - 1] = 7;
mx[i - 1] = 4;
}
}
if (lss(mx, v)) {
len = v.size() + 2;
for (int i = 1; i <= len; i++) {
if (i <= len / 2)
cout << 4;
else
cout << 7;
}
return 0;
}
if (lss(v, mn)) {
print(mn);
return 0;
}
res = v;
int pos = 0;
while (pos < (int)res.size() && (res[pos] == 4 || res[pos] == 7)) pos++;
if (pos < (int)res.size()) {
if (res[pos] >= 0 && res[pos] < 4) {
res[pos] = 4;
for (int i = pos + 1; i < (int)res.size(); i++) res[i] = 4;
} else if (res[pos] > 4 && res[pos] < 7) {
res[pos] = 7;
for (int i = pos + 1; i < (int)res.size(); i++) res[i] = 4;
} else if (res[pos] > 7) {
while (pos >= 0 && res[pos] >= 7) pos--;
res[pos] = 7;
for (int i = pos + 1; i < (int)res.size(); i++) res[i] = 4;
}
}
ct4 = 0, ct7 = 0;
for (int i = 0; i < (int)res.size(); i++) {
ct4 += (res[i] == 4);
ct7 += (res[i] == 7);
}
if (ct4 == ct7) {
print(res);
return 0;
}
if (ct4 > ct7) {
int pos = res.size() - 1;
while (ct4 != ct7) {
while (res[pos] == 7) pos--;
res[pos] = 7;
ct4--;
ct7++;
}
print(res);
return 0;
}
if (ct7 > ct4) {
int buf = ct4;
int pos = res.size() - 1;
while (1) {
while (res[pos] == 7) pos--;
if (buf - 1 + res.size() - 1 - pos >= res.size() / 2) {
res[pos] = 7;
pos++;
while (pos < (int)res.size()) {
res[pos] = 4;
pos++;
}
break;
} else {
res[pos] = 7;
buf--;
}
}
}
ct4 = 0, ct7 = 0;
for (int i = 0; i < (int)res.size(); i++) {
ct4 += (res[i] == 4);
ct7 += (res[i] == 7);
}
if (ct4 == ct7) {
print(res);
return 0;
}
if (ct4 > ct7) {
int pos = res.size() - 1;
while (ct4 != ct7) {
while (res[pos] == 7) pos--;
res[pos] = 7;
ct4--;
ct7++;
}
print(res);
return 0;
}
}
}
|
#include <bits/stdc++.h>
const int maxn = 1e5 + 10;
using namespace std;
char str[maxn], ans[maxn];
int n, a[maxn];
bool dfs(int pos, int cnt4, int cnt7, bool flag) {
if (pos == n) return true;
if (flag) {
for (int i = 1; i <= cnt4; i++) ans[pos++] = '4';
for (int i = 1; i <= cnt7; i++) ans[pos++] = '7';
return true;
}
if (a[pos] <= 4 && cnt4) {
if (dfs(pos + 1, cnt4 - 1, cnt7, a[pos] < 4)) {
ans[pos] = '4';
return true;
}
}
if (a[pos] <= 7 && cnt7) {
if (dfs(pos + 1, cnt4, cnt7 - 1, a[pos] < 7)) {
ans[pos] = '7';
return true;
}
}
return false;
}
int main() {
scanf("%s", str);
n = strlen(str);
for (int i = 0; i < n; i++) a[i] = str[i] - '0';
if (n & 1) {
int temp = (n + 1) / 2;
for (int i = 1; i <= temp; i++) cout << 4;
for (int i = 1; i <= temp; i++) cout << 7;
return 0;
} else if (!dfs(0, n / 2, n / 2, 0)) {
int temp = (n + 2) / 2;
for (int i = 1; i <= temp; i++) cout << 4;
for (int i = 1; i <= temp; i++) cout << 7;
return 0;
}
for (int i = 0; i < n; i++) printf("%c", ans[i]);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
using namespace std;
int ni() {
int _num;
scanf("%d", &_num);
return _num;
}
int testnum;
void preprocess() {}
string s, t;
bool dfs(int i, int four, int seven, bool slack) {
if (four == 0 && seven == 0) return true;
if (slack) {
t.insert(t.end(), four, '4');
t.insert(t.end(), seven, '7');
return true;
}
if (four && s[i] <= '4') {
t.insert(i, 1, '4');
if (s[i] < '4') return dfs(i + 1, four - 1, seven, true);
if (dfs(i + 1, four - 1, seven, false)) return true;
t.erase(((int)(t.size())) - 1);
}
if (seven && s[i] <= '7') {
t.insert(i, 1, '7');
if (s[i] < '7') return dfs(i + 1, four, seven - 1, true);
if (dfs(i + 1, four, seven - 1, false)) return true;
t.erase(((int)(t.size())) - 1);
}
return false;
}
void solve() {
if (((int)(s.size())) % 2) s = '0' + s;
while (true) {
int L = ((int)(s.size()));
if (dfs(0, L / 2, L / 2, false)) break;
s = "00" + s;
}
cout << t << endl;
}
bool input() {
cin >> s;
return true;
}
int main() {
preprocess();
int T = 1;
for (testnum = 1; testnum <= T; testnum++) {
if (!input()) break;
solve();
}
}
|
#include <bits/stdc++.h>
using namespace std;
bool superLucky(long long num) {
int fourCtr, sevenCtr;
fourCtr = sevenCtr = 0;
while (num > 0) {
if (num % 10 == 4) {
fourCtr++;
} else {
sevenCtr++;
}
num /= 10;
}
if (fourCtr == sevenCtr) {
return true;
} else
return false;
}
int main() {
int n;
cin >> n;
for (int i = 0;; i++) {
int j = i;
long long p = 1;
long long s = 0;
while (j >= 0) {
if (j % 2 == 0) {
s += (p * 4);
} else {
s += (p * 7);
}
p *= 10;
j = (j / 2) - 1;
}
if (s >= n && superLucky(s)) {
cout << s << endl;
return 0;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char ch[100000 + 2];
int len;
vector<int> ans;
int cnt[10];
bool flag;
void push(int c, int x) {
while (x--) {
ans.push_back(c);
}
}
bool dfs(int x) {
if (x == len) return false;
if (ch[x] < '4') {
push(4, len - x);
} else if (ch[x] == '4') {
push(4, 1);
if (dfs(x + 1)) {
ans[x] = 7;
}
} else if (ch[x] < '7') {
push(7, 1);
push(4, len - x - 1);
} else if (ch[x] == '7') {
push(7, 1);
if (dfs(x + 1)) {
while (~x) {
if (ans[x] == 7)
ans[x] = 4;
else
break;
--x;
}
if (x == -1)
flag = true;
else
ans[x - 1] = 7;
}
} else {
push(4, len - x);
return true;
}
return false;
}
void print(int t, int x) {
while (t--) {
printf("%d", x);
}
}
int main() {
scanf("%s", ch);
len = strlen(ch);
if (dfs(0)) flag = true;
if (flag || (len & 1)) {
if (flag) ++len;
print((len + 1) / 2, 4);
print((len + 1) / 2, 7);
} else {
int i;
for (i = 0; i < len; ++i) ++cnt[ans[i]];
cnt[0] = (cnt[4] - cnt[7]) / 2;
if (cnt[0] >= 0) {
i = len - 1;
while (cnt[0]--) {
while (ans[i] == 7) --i;
ans[i] = 7;
}
for (i = 0; i < ans.size(); ++i) printf("%d", ans[i]);
} else {
for (i = len - 1; ~i; --i) {
if (ans[i] == 7)
++cnt[0];
else {
if (cnt[0] > 0) break;
}
}
if (i == -1) {
print(len / 2 + 1, 4);
print(len / 2 + 1, 7);
} else {
for (int j = 0; j < i; ++j) printf("%d", ans[j]);
print(1, 7);
print(len - i - cnt[0], 4);
print(cnt[0] - 1, 7);
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
const int N = 1e5 + 5, M = 1e3 + 5, OO = 0x3f3f3f3f;
long long n;
set<long long> st;
bool super(long long x) {
int f = 0, s = 0, e = 0;
while (x) {
if (x % 10 == 4)
f++;
else if (x % 10 == 7)
s++;
else
e++;
x /= 10;
}
return f == s && !e;
}
void generate47(long long x = 0) {
if (x != 0 && super(x)) st.insert(x);
if (x > 1e9) return;
generate47(x * 10 + 4);
generate47(x * 10 + 7);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
if (super(n)) return cout << n, 0;
generate47();
cout << *upper_bound((st).begin(), (st).end(), n);
return 0;
}
|
#include <bits/stdc++.h>
int main() {
char s[1000001];
int n, f = -1, i;
int a[100000] = {0};
scanf("%s", s);
n = strlen(s);
if (n % 2 == 1) {
for (i = 0; i < n / 2 + 1; i++) putchar('4');
for (i = 0; i < n / 2 + 1; i++) putchar('7');
puts("");
return 0;
}
for (i = 0; i < n; i++) {
if (s[i] == '4') {
f = i;
continue;
} else if (s[i] < '4') {
for (; i < n; i++) s[i] = '4';
break;
} else if (s[i] < '7') {
s[i] = '7';
for (i++; i < n; i++) s[i] = '4';
break;
} else if (s[i] > '7') {
if (f == -1) {
for (i = 0; i < n / 2 + 1; i++) putchar('4');
for (i = 0; i < n / 2 + 1; i++) putchar('7');
puts("");
return 0;
} else {
s[f] = '7';
for (i = f + 1; i < n; i++) s[i] = '4';
}
}
}
f = 0;
for (i = 0; i < n; i++) {
if (s[i] == '4') f++;
a[i] = i + 1 - f;
}
if (f * 2 > n) {
for (i = n - 1; i >= 0; i--) {
if (s[i] == '4') {
s[i] = '7';
f--;
if (f * 2 == n) break;
}
}
} else if (f * 2 < n) {
for (i = n - 1; i >= 0; i--) {
if (s[i] == '4' && a[i] < n / 2) {
int x = a[i];
s[i] = '7';
for (i++; i < n / 2 + x + 1; i++) s[i] = '4';
for (; i < n; i++) s[i] = '7';
break;
}
}
if (i < 0) {
for (i = 0; i < n / 2 + 1; i++) putchar('4');
for (i = 0; i < n / 2 + 1; i++) putchar('7');
puts("");
return 0;
}
}
printf("%s\n", s);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int n;
char cmd[101000], str[101000];
bool DFS(int pos, int n4, int n7, bool limit) {
if (n4 == 0 && n7 == 0) return 1;
if (limit) {
if (n4) {
str[pos] = '4';
return DFS(pos + 1, n4 - 1, n7, limit);
} else {
str[pos] = '7';
return DFS(pos + 1, n4, n7 - 1, limit);
}
} else {
int ret;
if (cmd[pos] <= '4' && n4) {
str[pos] = '4';
if (cmd[pos] < '4')
ret = DFS(pos + 1, n4 - 1, n7, 1);
else
ret = DFS(pos + 1, n4 - 1, n7, 0);
if (ret) return 1;
}
if (cmd[pos] <= '7' && n7) {
str[pos] = '7';
if (cmd[pos] < '7')
ret = DFS(pos + 1, n4, n7 - 1, 1);
else
ret = DFS(pos + 1, n4, n7 - 1, 0);
if (ret) return 1;
}
}
return 0;
}
int main() {
while (~scanf("%s", cmd)) {
n = strlen(cmd);
if (n & 1 || !DFS(0, n / 2, n / 2, 0)) {
for (int i = 0; i < n / 2 + 1; ++i) printf("4");
for (int i = 0; i < n / 2 + 1; ++i) printf("7");
puts("");
} else
puts(str);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long n, n1, n2, mini, mini2;
bool f, f2;
void countfour(long long t1) {
int c4 = 0, c7 = 0;
if (f && mini < t1) return;
string s = to_string(t1);
for (int i = 0; i < s.size(); ++i) {
if (s[i] == '4')
c4++;
else
c7++;
}
if (s.size() % 2 == 0 && (abs(c4 - c7) >= 1) && t1 >= n) return;
if (s.size() % 2 == 0 && (c4 == 0 || c7 == 0) && t1 >= n) return;
if (t1 >= n && c4 == c7 && mini > t1) {
mini = t1;
n1 = t1;
f = 1;
return;
}
countfour((t1 * 10) + 4);
countfour((t1 * 10) + 7);
}
void countseven(long long t2) {
int c4 = 0, c7 = 0;
if (f2 && mini2 < t2) return;
string s = to_string(t2);
for (int i = 0; i < s.size(); ++i) {
if (s[i] == '4')
c4++;
else
c7++;
}
if (s.size() % 2 == 0 && (abs(c4 - c7) >= 1) && t2 >= n) return;
if (s.size() % 2 == 0 && (c4 == 0 || c7 == 0) && t2 >= n) return;
if (t2 >= n && c4 == c7 && mini2 > t2) {
mini2 = t2;
n2 = t2;
f2 = 1;
return;
}
countseven((t2 * 10) + 4);
countseven((t2 * 10) + 7);
}
int main() {
cin >> n;
mini = mini2 = 999999999999;
f = f2 = 0;
countfour(4);
countseven(7);
if (n1 == 0)
cout << n2 << endl;
else if (n2 == 0)
cout << n1 << endl;
else {
cout << min(n1, n2) << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const double Pi = acos(-1.0);
const int inf = 1000000007;
const long long llinf = 800000000000000119;
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int __builtin_popcount(long long x) {
int res = 0;
while (x) {
res += x & 1;
x >>= 1;
}
return res;
}
string to_string(string s) {
return '"' + s + '"';
return s;
}
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) {
return (b ? "true" : "false");
return to_string((int)b);
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
bool first = true;
string res = "{";
for (const auto& x : v) {
if (!first) {
res += ", ";
}
first = false;
res += to_string(x);
}
res += "}";
return res;
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << to_string(H);
debug_out(T...);
}
template <class T>
ostream& operator<<(ostream& stream, vector<T> v) {
for (T i : v) {
stream << i << " ";
}
stream << "\b";
return stream;
}
void hi() { printf("hi\n"); }
void hi(string flag) {
cerr << "["
<< "\"hi (%s)\\n\", flag.c_str()"
<< "]:",
debug_out("hi (%s)\n", flag.c_str());
}
int n;
int main() {
string s;
cin >> s;
n = s.size();
int bad = 2;
for (int i = 0; i < n / 2; i++) {
if (s[i] < '7') {
bad = 0;
break;
}
if (s[i] > '7') {
bad = 1;
break;
}
}
if (bad == 2) {
for (int i = n / 2; i < n; i++) {
if (s[i] < '4') {
bad = 0;
break;
}
if (s[i] > '4') break;
}
}
if (n % 2 == 1 || bad) {
for (int i = 0; i < (n + 2) / 2; i++) {
cout << 4;
}
for (int i = 0; i < (n + 2) / 2; i++) {
cout << 7;
}
cout << endl;
return 0;
}
int ind = 0, num4 = 0, num7 = 0;
string ans;
while (ind < n) {
if (s[ind] == '4')
num4++;
else if (s[ind] == '7')
num7++;
else
break;
ans += s[ind];
ind++;
}
if (ind < n) {
if (s[ind] > '7') {
int x = ind - 1;
while (x >= 0 && ans[x] == '7') {
ans[x] = '4';
num7--;
num4++;
x--;
}
ans[x] = '7';
num4--;
num7++;
} else if (s[ind] > '4') {
ans += '7';
num7++;
ind++;
} else {
ans += '4';
num4++;
ind++;
}
}
int z = ind - 1;
while (num7 > n / 2) {
while (ans[z] == '7') {
ans[z] = '4';
num4++;
num7--;
z--;
}
ans[z] = '7';
num4--;
num7++;
}
z = ind - 1;
while (z >= 0 && num4 > n / 2) {
if (ans[z] == '4') {
ans[z] = '7';
num7++;
num4--;
}
z--;
}
for (int i = num4; i < n / 2; i++) {
ans += '4';
}
for (int i = num7; i < n / 2; i++) {
ans += '7';
}
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string findNthNo(int n) {
string res = "";
while (n >= 1) {
if (n & 1) {
res = res + "4";
n = (n - 1) / 2;
} else {
res = res + "7";
n = (n - 2) / 2;
}
}
reverse(res.begin(), res.end());
return res;
}
bool eq(string n) {
long long int first = 0, second = 0;
for (long long int(i) = (0); (i) < (n.length()); (i) += (1))
if (n[i] == '4')
first++;
else
second++;
return first == second;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cout << fixed;
cout << setprecision(10);
;
int T = 1;
while (T--) {
string n = "0";
long long int second, k = 1, first = 0, s1 = 0;
cin >> second;
while (stoll(n) < second || !eq(n)) n = findNthNo(k++);
cout << n;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string num;
int len;
string big, sma;
bool bigThan(string a, string b) {
if (a.size() > b.size())
return true;
else if (a.size() < b.size())
return false;
else {
for (int i = 0; i < a.size(); ++i)
if (((int)a[i] - (int)b[i]) > 0)
return true;
else if (((int)a[i] < (int)b[i]))
return false;
}
return false;
}
int main() {
cin >> num;
len = num.size() % 2 == 0 ? num.size() : num.size() + 1;
for (int i = 0; i < len / 2; ++i) {
big += '7';
sma += '4';
}
for (int i = 0; i < len / 2; ++i) {
big += '4';
sma += '7';
}
if (bigThan(num, big)) {
cout << '4' << sma << '7' << endl;
} else if (bigThan(sma, num)) {
cout << sma << endl;
} else {
int index = -1;
char tar = '7';
for (int i = 0; i < num.size(); ++i) {
if (num[i] != '4' && num[i] != '7') {
index = i;
tar = num[i];
break;
}
}
if (tar == '7') {
} else if (tar > '7') {
for (int i = index - 1; i >= 0; --i) {
if (num[i] == '7') {
num[i] = '4';
} else if (num[i] == '4') {
num[i] = '7';
break;
}
}
for (int i = index; i < num.size(); ++i) {
num[i] = '4';
}
} else if (tar > '4') {
num[index] = '7';
for (int i = index + 1; i < num.size(); ++i) num[i] = '4';
} else {
for (int i = index; i < num.size(); ++i) num[i] = '4';
}
int c7 = 0, c4 = 0;
for (int i = 0; i < num.size(); ++i) {
if (num[i] == '7')
++c7;
else if (num[i] == '4')
++c4;
}
if (c4 < c7) {
for (int i = num.size() - 1; i >= 0; --i) {
if (num[i] != '4') {
num[i] = '4';
c4++;
c7--;
if (c4 == c7) break;
}
}
for (int i = num.size() - 1; i >= 0; --i) {
if (num[i] == '7' && num[i - 1] == '4') {
num[i] = '4';
num[i - 1] = '7';
for (int j = i + 1; j < num.size(); ++j) {
if (num[j] != '4') {
num[j] = '4';
c4++;
c7--;
}
}
break;
}
}
}
if (c4 > c7)
for (int i = num.size() - 1; i >= 0; --i) {
if (num[i] != '7') {
num[i] = '7';
c4--;
c7++;
if (c4 == c7) break;
}
}
cout << num << endl;
}
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100010];
char s2[100010];
char r[100010];
int n;
inline bool menor(char *s1, char *s2) {
for (int i = 0; s1[i] != '\0'; i++)
if (s1[i] < s2[i])
return true;
else if (s1[i] > s2[i])
return false;
return false;
}
bool vai(int u, int saldo, bool ve) {
if (u == n) return saldo == 0;
if ((saldo >= 0 ? saldo : -(saldo)) > (n - u)) return false;
bool pode4 = true;
if (ve) {
if ('4' < s[u]) pode4 = false;
}
if (pode4) {
r[u] = '4';
if (vai(u + 1, saldo - 1, (ve && s[u] == '4') ? true : false)) return true;
}
bool pode7 = true;
if (ve) {
if ('7' < s[u]) pode7 = false;
}
if (pode7) {
r[u] = '7';
if (vai(u + 1, saldo + 1, (ve && s[u] == '7') ? true : false)) return true;
}
return false;
}
int main() {
scanf("%s", s);
n = strlen(s);
if ((n % 2) == 1) {
n++;
for (int i = 0; i < n / 2; i++) printf("4");
for (int i = 0; i < n / 2; i++) printf("7");
printf("\n");
return 0;
}
for (int i = 0; i < n / 2; i++) s2[i] = '4';
for (int i = n / 2; i < n; i++) s2[i] = '7';
s2[n] = '\0';
if (!menor(s2, s)) {
for (int i = 0; i < n / 2; i++) printf("4");
for (int i = 0; i < n / 2; i++) printf("7");
printf("\n");
return 0;
}
for (int i = 0; i < n / 2; i++) s2[i] = '7';
for (int i = n / 2; i < n; i++) s2[i] = '4';
s2[n] = '\0';
if (menor(s2, s)) {
n += 2;
for (int i = 0; i < n / 2; i++) printf("4");
for (int i = 0; i < n / 2; i++) printf("7");
printf("\n");
return 0;
}
vai(0, 0, true);
for (int i = 0; i < n; i++) printf("%c", r[i]);
printf("\n");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string crem(int c4, int c7) {
string ans = "";
for (int i = 0, _n = c4; i < _n; i++) ans += "4";
for (int i = 0, _n = c7; i < _n; i++) ans += "7";
return ans;
}
int main() {
string line, ans = "";
int n;
cin >> line;
n = line.length();
if (n % 2) {
n++;
cout << crem(n / 2, n / 2) << "\n";
} else if (line[0] > '7')
cout << crem((n + 2) / 2, (n + 2) / 2) << "\n";
else {
int c4 = n / 2, c7 = n / 2;
bool gtr = false;
int locc4 = -1, locc7 = -1;
for (int i = 0, _n = n; i < _n; i++) {
if (gtr) {
cout << ans + crem(c4, c7) << "\n";
return 0;
} else if (line[i] <= '4') {
if (c4) {
ans += "4";
c4--;
if (line[i] < '4') gtr = true;
} else {
ans += '7';
c7--;
gtr = true;
}
} else if (line[i] <= '7' && c7) {
ans += "7";
c7--;
if (line[i] < '7') gtr = true;
} else {
bool ok = false;
for (int c = i - 1; c >= 0; c--) {
if (ans[c] == '7')
c7++;
else if (ans[c] == '4') {
c4++;
if (c7 > 0) {
ans[c] = '7';
c7--;
ok = true;
for (int j = 0, _n = c + 1; j < _n; j++) cout << ans[j];
cout << crem(c4, c7) << "\n";
return 0;
}
}
}
if (!ok) {
cout << crem((n + 2) / 2, (n + 2) / 2) << "\n";
return 0;
}
}
}
cout << ans << "\n";
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 100024;
char ch[N];
int ans[N], c[10], newwpos;
bool found;
bool check(int Nn) {
for (int i = 1; i <= Nn; i++) {
int nownum = ch[i] - '0', nowmost = i <= Nn / 2 ? 7 : 4;
if (nownum == nowmost)
continue;
else if (nownum > nowmost)
return false;
else
return true;
}
return true;
}
int main() {
scanf("%s", ch + 1);
int n = strlen(ch + 1);
if (n % 2 == 1 || !check(n)) {
n += n % 2 ? 1 : 2;
for (int i = 1; i <= n; i++) cout << (i <= n / 2 ? 4 : 7);
return 0;
}
int bef = -1, newwpos = n;
for (int i = 1; i <= n; i++) {
int nownum = ch[i] - '0';
if (nownum == 7 || nownum == 4)
c[ans[i] = nownum]++, bef = (ans[i] == 4 && !found ? i : bef);
else if (nownum < 7 && nownum != 4)
ans[i] = nownum < 4 ? 4 : 7, c[ans[i]]++, newwpos = i,
bef = (ans[i] == 4 && found ? i : bef);
if (c[4] > n / 2)
newwpos = i, ans[newwpos] = 7;
else if (c[7] == n / 2)
found = 1;
else if (c[7] > n / 2 || nownum > 7)
newwpos = bef, ans[newwpos] = 7;
if (newwpos != n) break;
}
c[4] = 0, c[7] = 0;
for (int i = 1; i <= newwpos; i++) {
cout << ans[i];
c[ans[i]]++;
}
for (int i = 1; i <= (n / 2) - c[4]; i++) cout << 4;
for (int i = 1; i <= (n / 2) - c[7]; i++) cout << 7;
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;
void form(string s) {
int len = s.size();
if (len % 2 == 1) {
len++;
}
for (int i = 0; i < len / 2; i++) printf("4");
for (int j = 0; j < len / 2; j++) printf("7");
printf("\n");
exit(0);
}
string converttolucky(string s) {
int flag = 0;
for (int i = 0; i < s.size(); i++) {
if (s[i] == '4' || s[i] == '7') {
continue;
} else {
if (s[i] < '4') {
s[i] = '4';
for (int j = i + 1; j < s.size(); j++) s[j] = '4';
return s;
} else if (s[i] < '7') {
s[i] = '7';
for (int j = i + 1; j < s.size(); j++) s[j] = '4';
return s;
} else {
flag = 0;
for (int k = i - 1; k >= 0; k--) {
if (s[k] == '4') {
flag = 1;
s[k] = '7';
for (int j = k + 1; j < s.size(); j++) {
s[j] = '4';
}
return s;
}
}
if (flag == 0) {
s.append("4");
form(s);
}
}
}
}
return s;
}
string more4(string s) {
int len4 = 0;
int len7 = 0;
for (int i = 0; i < s.size(); i++) {
if (s[i] == '4')
len4++;
else
len7++;
}
if (len4 >= len7) return s;
int flag = 0;
int rem4 = 0;
int rem7 = 0;
for (int j = s.size() - 1; j >= 0; j--) {
if (s[j] == '4') {
int tmp7 = len7 - rem7 + 1;
rem4++;
int tmp4 = len4 - rem4;
if (tmp4 + (s.size() - j - 1) >= tmp7) {
s[j] = '7';
for (int k = j + 1; k < s.size(); k++) s[k] = '4';
return s;
}
} else
rem7++;
}
s.append("4");
form(s);
}
string solve(string s) {
int len4 = 0;
int len7 = 0;
for (int i = 0; i < s.size(); i++) {
if (s[i] == '4')
len4++;
else
len7++;
}
for (int j = s.size() - 1; j >= 0; j--) {
if (len4 == len7) {
cout << s << "\n";
return s;
}
if (s[j] == '4') {
s[j] = '7';
len4--;
len7++;
}
}
assert(len4 == len7);
}
int main() {
string s;
cin >> s;
int len = s.size();
if (len % 2 == 1) form(s);
s = converttolucky(s);
s = more4(s);
solve(s);
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
string in;
cin >> in;
long long inp = stoll(in);
int n = in.size();
string ans;
int cnt;
cnt = n / 2;
if (n % 2 == 1) {
cnt++;
}
while (cnt > 0) {
ans += "4";
cnt--;
}
cnt = ans.size();
while (cnt > 0) {
ans += "7";
cnt--;
}
int ok = 0;
do {
long long nw = stoll(ans);
if (nw >= inp) {
ok++;
break;
}
} while (next_permutation(ans.begin(), ans.end()));
if (ok == 0) {
cout << "4";
}
cout << ans;
if (ok == 0) {
cout << "7";
}
cout << "\n";
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string n, s;
long long ok, a, b;
int main() {
cin >> n;
if (n.size() & 1) n = string(n.size() + 1, '4');
for (int i = n.size() - 1; i >= 0; i--) {
if (n[i] < '4') {
a = s.size() + 1;
s.clear();
s = string(a, '4');
b = 0;
ok = 0;
} else if (n[i] == '4') {
if (ok == 0) {
s += '4';
a++;
} else {
a = s.size();
s.clear();
s = string(a, '4');
s += '7';
ok = 0;
b = 1;
}
} else if (n[i] < '7') {
a = s.size();
s.clear();
s = string(a, '4');
s += '7';
ok = 0;
b = 1;
} else if (n[i] == '7') {
if (ok == 0) {
s += '7';
b++;
} else {
a = s.size() + 1;
s.clear();
s = string(a, '4');
ok = 3;
b = 0;
}
} else {
s += '4';
a++;
ok = 3;
}
}
if (ok != 0) {
s = string(n.size() + 2, '4');
a = n.size() + 2;
b = 0;
}
if (a < b) {
for (int i = 0; i < s.size(); i++) {
if (s[i] == '4') {
s[i] = '7';
a--;
b++;
for (int j = i - 1; j >= 0; j--) {
if (s[j] == '7') {
b--;
a++;
s[j] = '4';
}
}
}
if (a >= b) break;
}
if (b > a) {
a = s.size() + 2;
s.clear();
s = string(a, '4');
b = 0;
}
}
reverse(s.begin(), s.end());
long long dif = abs(a - b);
for (int i = s.size() - 1; i >= 0; i--) {
if (dif == 0) break;
if (s[i] == '4') s[i] = '7', dif -= 2;
}
cout << s;
}
|
#include <bits/stdc++.h>
using namespace std;
const int mod = (int)1e6 + 3;
const int inf = (int)1e9;
const int base = 10;
int main() {
string s;
getline(cin, s);
int n = (int)s.size();
if (n % 2 == 1)
cout << string((n + 1) / 2, '4') + string((n + 1) / 2, '7');
else if (string(n / 2, '7') + string(n / 2, '4') < s) {
cout << string((n + 2) / 2, '4') + string((n + 2) / 2, '7');
} else {
string ans = "";
bool f = true;
for (int i = 0; i < n && f; ++i) {
if (s[i] < '4') {
f = false;
ans += '4';
} else if (s[i] != '4' && s[i] < '7') {
f = false;
ans += '7';
} else if (s[i] != '4' && s[i] != '7' && s[i] > '7') {
ans += '4';
bool ost = true;
for (int j = (int)ans.size() - 2; j >= 0 && ost; --j) {
if (ans[j] == '4') {
ost = false;
ans[j] = '7';
}
}
} else
ans += s[i];
}
int a = 0;
int b = 0;
for (int i = 0; i < (int)ans.size(); i++)
if (ans[i] == '4')
a++;
else
b++;
a = (n / 2) - a;
b = (n / 2) - b;
if (a < 0 || b < 0) {
if (a < 0) {
b += a;
for (int i = (int)ans.size() - 1; i >= 0 && a < 0; --i) {
if (ans[i] == '4') {
ans[i] = '7';
a++;
}
}
cout << ans + string(b, '7');
} else {
int j = (int)ans.size() - 1;
while (j >= 0 && (ans[j] != '4' || b <= 0)) {
if (ans[j] == '7') b++;
j--;
}
if (j < 0) {
n += 2;
cout << string(n / 2, '4') + string(n / 2, '7');
} else {
ans[j] = '7';
string cur = "";
int a = 0;
int b = 0;
for (int i = 0; i < j + 1; i++) {
cur += ans[i];
if (ans[i] == '4')
a++;
else
b++;
}
a = (n / 2) - a;
b = (n / 2) - b;
cout << cur + string(a, '4') + string(b, '7');
}
}
} else
cout << ans + string(a, '4') + string(b, '7');
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
vector<long long> v;
void slucky(long long n, long long f, long long s) {
if (n >= 1e10) return;
if (f == s) v.push_back(n);
slucky(n * 10 + 4, f + 1, s);
slucky(n * 10 + 7, f, s + 1);
}
int main() {
long long a;
cin >> a;
slucky(0, 0, 0);
sort(v.begin(), v.end());
for (long long i = 0; 1; i++) {
if (a <= v[i]) {
cout << v[i] << endl;
return 0;
}
}
}
|
#include <bits/stdc++.h>
#pragma GCC optimize "trapv"
using namespace std;
vector<string> v;
void printAllKLengthRec(char set[], string prefix, long long int n,
long long int k) {
if (k == 0) {
if (count(prefix.begin(), prefix.end(), '4') ==
count(prefix.begin(), prefix.end(), '7'))
v.push_back(prefix);
return;
}
for (long long int i = 0; i < n; i++) {
string newPrefix;
newPrefix = prefix + set[i];
printAllKLengthRec(set, newPrefix, n, k - 1);
}
}
void printAllKLength(char set[], long long int k, long long int n) {
printAllKLengthRec(set, "", n, k);
}
int32_t main() {
ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
;
long long int s;
cin >> s;
char set[] = {'4', '7'};
for (long long int i = 2; i <= 10; i += 2) {
printAllKLength(set, i, 2);
}
for (long long int i = 0; i < v.size(); i++) {
stringstream str(v[i]);
long long int x = 0;
str >> x;
if (x >= s) {
cout << x;
break;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
static string s, t;
cin >> s;
int n = s.size();
if (!(n & 1))
if (string(n / 2, '7') + string(n / 2, '4') < s)
cout << string(n / 2 + 1, '4') << string(n / 2 + 1, '7') << endl;
else {
int n4 = n / 2, n7 = n / 2;
bool flag = 0;
for (int i = 0; i < n; ++i) {
bool ok = 0;
if (n4 > 0) {
if (flag || s[i] < '4')
ok = 1;
else if (s[i] == '4')
for (int j = i + 1; j <= n; ++j) {
if (j == n) {
ok = 1;
break;
}
char ch = (j <= i + n7 ? '7' : '4');
if (ch > s[j]) ok = 1;
if (ch != s[j]) break;
}
}
if (ok)
t += "4", --n4;
else
t += "7", --n7;
if (t[i] > s[i]) flag = 1;
}
cout << t << endl;
}
else
cout << string(n / 2 + 1, '4') << string(n / 2 + 1, '7') << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const long long mxn = 1e9 + 7;
const long long inf = 1e18;
vector<long long> vec;
void fun(long long n, long long four, long long seven) {
if (n > mxn) {
return;
}
long long tem1 = (10 * n) + 4;
if ((four + 1) == seven) {
vec.push_back(tem1);
}
fun(tem1, four + 1, seven);
long long tem2 = (10 * n) + 7;
if (four == (seven + 1)) {
vec.push_back(tem2);
}
fun(tem2, four, seven + 1);
return;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
;
long long i, j, k, a, b, c, d, n, m, t, u, v, w, x, y, z;
cin >> n;
fun(0, 0, 0);
sort(vec.begin(), vec.end());
long long pos = lower_bound(vec.begin(), vec.end(), n) - vec.begin();
long long ans = vec[pos];
cout << ans << "\n";
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long ans = 1e11, n;
void lucky(long long a, long long s) {
if (a < ans) {
if (a >= n && s == 0)
ans = a;
else {
lucky(a * 10 + 4, s + 1);
lucky(a * 10 + 7, s - 1);
}
}
}
int main() {
cin >> n;
lucky(0, 0);
cout << ans;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
string s;
cin >> s;
if (s.size() % 2) {
s += "0";
string tmp = "";
for (int i = 0; i < s.size() / 2; i++) tmp += "4";
for (int i = 0; i < s.size() / 2; i++) tmp += "7";
cout << tmp << endl;
return 0;
}
string tmp = "";
for (int i = 0; i < s.size() / 2; i++) {
tmp += "4";
}
for (int i = 0; i < s.size() / 2; i++) {
tmp += "7";
}
bool f = 0, ex = 0;
int sa = -1;
int ind = s.size() / 2;
int cnt = 0;
for (int i = 0; i < s.size(); i++) {
if (tmp[i] < s[i]) {
if (ind == s.size()) {
ex = 1;
break;
}
if (tmp[ind] < s[i]) {
ex = 1;
break;
} else if (tmp[ind] > s[i]) {
swap(tmp[ind], tmp[i]);
break;
} else {
swap(tmp[ind], tmp[i]);
}
ind++;
} else if (tmp[i] > s[i]) {
break;
}
if (tmp[i] == '4' && cnt < s.size() / 2) {
sa = i;
} else
cnt++;
}
if (sa != -1 && ex) {
string t = "";
int x = s.size() / 2;
int y = x;
for (int i = 0; i < sa; i++) {
t += tmp[i];
if (tmp[i] == '7')
x--;
else
y--;
}
if (x) {
t += "7";
x--;
for (int i = 0; i < y; i++) t += "4";
for (int i = 0; i < x; i++) t += "7";
if (t > s) {
cout << t << endl;
return 0;
}
}
}
if (ex) {
tmp += "47";
sort(tmp.begin(), tmp.end());
cout << tmp << endl;
} else
cout << tmp << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
void exceed(int j) {
int i;
j = j / 2;
for (i = 0; i < j; i++) cout << 4;
for (i = 0; i < j; i++) cout << 7;
}
int main() {
int sta[20];
int i, j, k, l, four = 0, seven = 0;
;
bool f = true;
char s[20];
scanf("%s", s);
j = strlen(s);
if (j % 2) {
exceed(j + 1);
return 0;
}
i = 0;
while (f && s[i] != 0) {
switch (s[i]) {
case '0':
case '1':
case '2':
case '3':
f = false;
sta[i] = 1;
four++;
for (k = i + 1; s[k] != 0; k++) {
if (four < j / 2) {
sta[k] = 1;
four++;
} else {
sta[k] = 2;
seven++;
}
}
break;
case '4':
sta[i] = 1;
four++;
break;
case '5':
case '6':
f = false;
sta[i] = 2;
for (k = i + 1; s[k] != 0; k++) {
if (four < j / 2) {
sta[k] = 1;
four++;
} else {
sta[k] = 2;
seven++;
}
}
break;
case '7':
if (seven < j / 2) {
sta[i] = 2;
seven++;
break;
}
case '8':
case '9':
f = false;
sta[i] = 1;
if (i == 0) {
exceed(j + 2);
return 0;
}
k = i - 1;
while (sta[k] == 2) {
sta[k] = 1;
k--;
if (k < 0) {
exceed(j + 2);
return 0;
}
}
sta[k] = 2;
four = 0;
seven = 0;
for (l = 0; l <= k; l++) {
if (sta[l] == 1)
four++;
else {
seven++;
if (seven > j / 2) {
exceed(j + 2);
return 0;
}
}
}
for (; s[l] != 0; l++) {
if (four < j / 2) {
sta[l] = 1;
four++;
} else {
sta[l] = 2;
seven++;
}
}
}
i++;
}
i = 0;
while (s[i] != 0) {
switch (sta[i]) {
case 1:
cout << 4;
break;
case 2:
cout << 7;
break;
}
i++;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
template <class T>
void pv(T a, T b) {
for (T i = a; i != b; ++i) cout << *i << " ";
cout << endl;
}
template <class T>
void pvp(T a, T b) {
for (T i = a; i != b; ++i)
cout << "(" << i->first << ", " << i->second << ") ";
cout << endl;
}
template <class T>
void chmin(T &t, T f) {
if (t > f) t = f;
}
template <class T>
void chmax(T &t, T f) {
if (t < f) t = f;
}
int in_c() {
int c;
for (; (c = getchar()) <= ' ';) {
if (!~c) throw ~0;
}
return c;
}
int in() {
int x = 0, c;
for (; (unsigned)((c = getchar()) - '0') >= 10;) {
if (c == '-') return -in();
if (!~c) throw ~0;
}
do {
x = (x << 3) + (x << 1) + (c - '0');
} while ((unsigned)((c = getchar()) - '0') < 10);
return x;
}
long long In() {
long long x = 0, c;
for (; (unsigned)((c = getchar()) - '0') >= 10;) {
if (c == '-') return -In();
if (!~c) throw ~0;
}
do {
x = (x << 3) + (x << 1) + (c - '0');
} while ((unsigned)((c = getchar()) - '0') < 10);
return x;
}
int sig(int x) { return (x < 0) ? -1 : (x > 0) ? +1 : 0; }
int M, N;
char SS[100020], *S;
char T[100020];
int pos[8][100020], val[8][100020];
bool greaterThan74() {
int i;
for (i = 0; i < N / 2; ++i) {
if (S[i] - '0' > 7) return 1;
if (S[i] - '0' < 7) return 0;
}
for (i = N / 2; i < N; ++i) {
if (S[i] - '0' > 4) return 1;
if (S[i] - '0' < 4) return 0;
}
return 0;
}
int main() {
int g;
int i;
for (; S = SS, ~scanf("%s", S);) {
N = strlen(S);
if (N % 2 != 0) ++N, *--S = '0';
if (greaterThan74()) ++N, *--S = '0';
if (N % 2 != 0) ++N, *--S = '0';
for (g = 4; g <= 7; ++g) {
pos[g][N] = N;
val[g][N] = 0;
for (i = N; i--;) {
if (S[i] - '0' != g) {
pos[g][i] = i;
val[g][i] = S[i] - '0';
} else {
pos[g][i] = pos[g][i + 1];
val[g][i] = val[g][i + 1];
}
}
}
int flg = 0;
int a4, a7;
a4 = a7 = N / 2;
for (i = 0; i < N; ++i) {
if (!a4) {
T[i] = '7';
} else if (!a7) {
T[i] = '4';
} else {
if (flg) {
T[i] = '4';
} else {
int cmp = 0;
if (pos[4][i] < i + 1) {
cmp += sig(4 - val[4][i]) * 1000000;
}
if (pos[7][i + 1] < i + 1 + a7) {
cmp += sig(7 - val[7][i + 1]) * 1000;
}
if (pos[4][i + 1 + a7] < N) {
cmp += sig(4 - val[4][i + 1 + a7]) * 1;
}
if (cmp >= 0) {
T[i] = '4';
} else {
T[i] = '7';
}
}
}
if (S[i] - '0' < T[i] - '0') {
flg = 1;
}
if (T[i] == '4') {
--a4;
} else {
--a7;
}
}
T[N] = 0;
puts(T);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long ans = 1e18, n;
void lest(long long current, long long counter4, long long counter7) {
if (current >= n) {
if (current < ans && counter4 == counter7) {
ans = current;
return;
}
if (current > n * 100) return;
}
lest(current * 10 + 7, counter4, counter7 + 1);
lest(current * 10 + 4, counter4 + 1, counter7);
}
int main() {
cin >> n;
lest(0, 0, 0);
cout << ans;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100010;
char temp[100010];
vector<int> ans;
bool dfs(int idx, int cnt4, int cnt7, bool bi, int len) {
if (bi || idx == len) {
for (int i = 0; i < cnt7; ++i) ans.push_back(7);
for (int i = 0; i < cnt4; ++i) ans.push_back(4);
return true;
}
if (cnt4 && temp[idx] <= '4' &&
dfs(idx + 1, cnt4 - 1, cnt7, temp[idx] < '4', len)) {
ans.push_back(4);
return true;
}
if (cnt7 && temp[idx] <= '7' &&
dfs(idx + 1, cnt4, cnt7 - 1, temp[idx] < '7', len)) {
ans.push_back(7);
return true;
}
return false;
}
int main(void) {
while (scanf("%s", temp) != EOF) {
int len = strlen(temp);
if (len % 2 == 1) {
for (int i = 0; i < len + 1; ++i) {
if (i < (len + 1) / 2)
printf("4");
else
printf("7");
}
printf("\n");
continue;
}
ans.clear();
if (dfs(0, len / 2, len / 2, false, len)) {
for (int i = ans.size() - 1; i >= 0; --i) printf("%d", ans[i]);
printf("\n");
} else {
for (int i = 0; i < len + 2; ++i) {
if (i < len / 2 + 1)
printf("4");
else
printf("7");
}
printf("\n");
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-6;
long long pw(long long b, long long p) {
if (!p) return 1;
long long sq = pw(b, p / 2);
sq *= sq;
if (p % 2) sq *= b;
return sq;
}
vector<long long> vec;
void gen(long long x, int cnt4, int cnt7, int n) {
if (cnt4 == cnt7 && x >= n) vec.push_back(x);
if (x >= 1e10) return;
gen(x * 10 + 4, cnt4 + 1, cnt7, n);
gen(x * 10 + 7, cnt4, cnt7 + 1, n);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
long long n;
cin >> n;
gen(0, 0, 0, n);
sort(vec.begin(), vec.end());
vector<long long>::iterator it = lower_bound(vec.begin(), vec.end(), n);
cout << *it << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
vector<long long> all;
void backtrack(long long x, int cnt4, int cnt7) {
if (x > 1e10) return;
if (cnt4 == cnt7) all.push_back(x);
long long nxt = x * 10 + 4;
backtrack(nxt, cnt4 + 1, cnt7);
nxt = x * 10 + 7;
backtrack(nxt, cnt4, cnt7 + 1);
}
int main() {
std::ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
int n;
cin >> n;
backtrack(0, 0, 0);
sort(all.begin(), all.end());
cout << *lower_bound(all.begin(), all.end(), n);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long n;
vector<long long> res;
void lucky(long long num) {
if (num > 1e10) {
return;
}
int count4 = 0, count7 = 0;
bool isSuper;
string s = to_string(num);
for (unsigned int i = 0; i < s.size(); i++) {
if (s[i] == '4')
count4++;
else
count7++;
}
(count4 == count7) ? isSuper = true : isSuper = false;
if (num > 0 && isSuper) res.push_back(num);
lucky(num * 10 + 4);
lucky(num * 10 + 7);
}
int main() {
ios_base::sync_with_stdio();
cin.tie(0);
cout.tie(0);
cin >> n;
lucky(0);
sort(res.begin(), res.end());
vector<long long>::iterator it = lower_bound(res.begin(), res.end(), n);
long long ans = it - res.begin();
cout << res[ans] << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 7;
const int M = 2e5 + 7;
const int inf = 1e9 + 7;
const long long base = 1e18;
const double pi = acos(-1);
const double ep = 1e-9;
string s;
int last = 0;
int ans[N];
void solve() {
cin >> s;
if (s.size() % 2 == 1) {
int t = (s.size() + 1) / 2;
for (int i = 0; i < t; i++) printf("%d", 4);
for (int i = 0; i < t; i++) printf("%d", 7);
return;
}
bool bg = false;
for (int i = 1; i < s.size() + 1; i++) {
if (bg) {
ans[i] = 4;
} else {
int c = s[i - 1] - '0';
if (c <= 4) {
ans[i] = 4;
if (c < 4) bg = true;
} else {
if (c <= 7) {
ans[i] = 7;
if (c < 7) bg = true;
} else {
if (ans[last] == 0)
ans[last] = 4;
else
ans[last] = 7;
bg = true;
for (int j = last + 1; j < i + 1; j++) ans[j] = 4;
}
}
}
if (!bg && ans[i] == 4) last = i;
}
int cnt4 = 0, cnt7 = 0;
for (int i = 0; i < s.size() + 1; i++)
if (ans[i] == 4)
cnt4++;
else if (ans[i] == 7)
cnt7++;
if ((cnt4 + cnt7) % 2 == 1 || cnt4 == 0) {
int t = (cnt4 + cnt7 + 1) / 2;
if (cnt4 == 0) t++;
for (int i = 0; i < t; i++) printf("%d", 4);
for (int i = 0; i < t; i++) printf("%d", 7);
return;
}
for (int i = s.size(); i >= 0; i--) {
if (cnt7 >= cnt4) {
break;
}
if (ans[i] == 4) {
ans[i] = 7;
cnt7++;
cnt4--;
}
}
if (cnt4 < cnt7) {
int j = -1;
int dem = 0;
for (int i = s.size(); i > -1; i--) {
if (ans[i] == 7)
dem++;
else {
if (ans[i] == 4 && cnt4 + dem - 1 >= cnt7 - dem + 1) {
ans[i] = 7;
j = i;
cnt4--;
cnt7++;
break;
}
}
}
if (j == -1) {
int t = (cnt4 + cnt7 + 2) / 2;
for (int i = 0; i < t; i++) cout << 4;
for (int i = 0; i < t; i++) cout << 7;
return;
}
for (int i = j + 1; i < s.size() + 1; i++) {
if (cnt4 == cnt7) break;
if (ans[i] == 7) {
ans[i] = 4;
cnt4++;
cnt7--;
}
}
}
for (int i = 0; i <= s.size(); i++)
if (ans[i] != 0) printf("%d", ans[i]);
}
int main() { solve(); }
|
#include <bits/stdc++.h>
using namespace std;
char s[100005];
int n;
char f[100005];
bool ans;
void dfs(int idx, int cnt4, int cnt7, int tight, char p[]) {
if (cnt4 > n / 2 || cnt7 > n / 2) return;
if (ans) return;
if (idx == n) {
ans = true;
printf("%s\n", p);
return;
}
if (ans) return;
if (tight == 1) {
if (s[idx] <= '4') {
if (!ans) {
p[idx] = '4';
dfs(idx + 1, cnt4 + 1, cnt7, !(s[idx] < '4'), p);
}
}
if (s[idx] <= '7') {
if (!ans) {
p[idx] = '7';
dfs(idx + 1, cnt4, cnt7 + 1, !(s[idx] < '7'), p);
}
}
} else {
if (!ans) {
p[idx] = '4';
dfs(idx + 1, cnt4 + 1, cnt7, 0, p);
}
if (!ans) {
p[idx] = '7';
dfs(idx + 1, cnt4, cnt7 + 1, 0, p);
}
}
}
int main() {
scanf("%s", &s);
char p[100005];
n = (int)strlen(s);
ans = false;
if (n % 2 == 0) dfs(0, 0, 0, 1, p);
if (!ans) {
if (n % 2 == 0)
n += 2;
else
n += 1;
for (int i = 0; i < n; i++) {
if (i < n / 2)
f[i] = '4';
else
f[i] = '7';
}
printf("%s\n", f);
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
vector<long long> vec;
bool che(long long x) {
long long c = 0, d = 0;
while (x > 0) {
if (x % 10 == 7)
c++;
else
d++;
x /= 10;
}
if (c == d)
return 1;
else
return 0;
}
void tec(long long x) {
if (x > 1e10) return;
if (che(x)) vec.push_back(x);
tec(x * 10 + 4);
tec(x * 10 + 7);
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
;
long long x;
cin >> x;
tec(7);
tec(4);
sort(vec.begin(), vec.end());
cout << *lower_bound(vec.begin(), vec.end(), x) << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
long long int n;
cin >> n;
string s;
while (true) {
s += "47";
sort(s.begin(), s.end());
do {
if (stoll(s) >= n) {
cout << stoll(s);
return 0;
}
} while (next_permutation(s.begin(), s.end()));
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int n;
string s, ret;
bool dfs(int idx, int four, int seven, bool flag) {
if (idx == n) return true;
if (flag) {
for (int i = 0; i < four; i++) ret[idx + i] = '4';
for (int i = four; i < four + seven; i++) ret[idx + i] = '7';
return true;
}
if (four > 0 && s[idx] <= '4' &&
dfs(idx + 1, four - 1, seven, s[idx] < '4')) {
ret[idx] = '4';
return true;
}
if (seven > 0 && s[idx] <= '7' &&
dfs(idx + 1, four, seven - 1, s[idx] < '7')) {
ret[idx] = '7';
return true;
}
return false;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> s;
n = s.length();
ret.resize(n);
if (n % 2 == 1 || !dfs(0, n / 2, n / 2, false)) {
int half = (n + 2) / 2;
for (int i = 0; i < half; i++) cout << '4';
for (int i = 0; i < half; i++) cout << '7';
cout << "\n";
} else
cout << ret << "\n";
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
template <class T>
T abs(T x) {
return x > 0 ? x : -x;
}
int n;
int m;
string s, res = "";
int check(int i, int j) {
if (n - i < abs(j)) return 0;
if (j >= 0) {
int a = 0, b = j, c = (n - i - j) / 2;
a += c;
b += c;
for (int i = 0; i < b; i++) res += '7';
for (int i = 0; i < a; i++) res += '4';
} else {
int a = -j, b = 0, c = (n - i + j) / 2;
a += c;
b += c;
for (int i = 0; i < b; i++) res += '7';
for (int i = 0; i < a; i++) res += '4';
}
return 1;
}
int go(int i, int j) {
if (i == n) return int(j == 0);
if (s[i] < '4' && check(i + 1, j + 1) || s[i] == '4' && go(i + 1, j + 1)) {
res += '4';
return 1;
}
if (s[i] < '7' && check(i + 1, j - 1) || s[i] == '7' && go(i + 1, j - 1)) {
res += '7';
return 1;
}
return 0;
}
int main() {
cin >> s;
n = ((int)(s).size());
if (n & 1) {
for (int i = 0; i < (n + 1) / 2; i++) printf("4");
for (int i = 0; i < (n + 1) / 2; i++) printf("7");
printf("\n");
return 0;
}
if (!go(0, 0)) {
for (int i = 0; i < (n + 2) / 2; i++) printf("4");
for (int i = 0; i < (n + 2) / 2; i++) printf("7");
printf("\n");
return 0;
} else {
reverse((res).begin(), (res).end());
printf("%s\n", res.c_str());
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s;
bool ch(string t) {
if (t.size() > s.size()) return true;
int i = 0;
while (i < s.size() && s[i] == t[i]) i++;
if (i == s.size() || t[i] > s[i]) return true;
return false;
}
int main() {
string t;
cin >> s;
int n = s.size();
if (n % 2 != 0) n++;
for (int i = 0; i < n / 2; i++) t += "4";
for (int i = 0; i < n / 2; i++) t += "7";
string e = t;
do {
if (ch(t)) {
cout << t << endl;
return 0;
}
} while (next_permutation(t.begin(), t.end()));
cout << 4 << e << 7 << endl;
}
|
#include <bits/stdc++.h>
#pragma comment(linker, "/stack:200000000")
using namespace std;
char s[101010];
int n, F, S;
int nn, a[101010];
int test() {
for (int i = 0; i < n / 2; i++)
if (s[i] > '7')
return true;
else if (s[i] < '7')
return false;
for (int i = n / 2; i < n; i++)
if (s[i] > '4')
return true;
else if (s[i] < '4')
return false;
return false;
}
int main() {
scanf("%s", s);
n = strlen(s);
int pox = 0;
if ((n & 1) || test())
cout << string((n + 2) / 2, '4') << string((n + 2) / 2, '7');
else {
for (int i = n - 1; i >= 0; i--)
if (s[i] > '7')
a[i] = (1 << 30);
else if (s[i] == '7')
a[i] = a[i + 1] + 1;
else if (s[i] > '4')
a[i] = 1;
else if (s[i] == '4')
a[i] = min(a[i + 1], 1);
else
a[i] = 0;
S = F = n / 2;
for (int i = 0; i < n; i++)
if (s[i] == '4')
if (F && a[i + 1] <= S) {
printf("4");
F--;
} else {
printf("7");
S--;
break;
}
else if (s[i] < '4') {
printf("4");
F--;
break;
} else if (s[i] < '7') {
printf("7");
S--;
break;
} else {
printf("7");
S--;
}
for (; F; F--) printf("4");
for (; S; S--) printf("7");
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline bool eps_dayu(const T &a, const T &b) {
return (a - b) > 1e-10 ? 1 : 0;
}
template <typename T>
inline bool eps_dengyu(const T &a, const T &b) {
if (a - b > 1e-10 || b - a > 1e-10) return 0;
return 1;
}
template <typename T>
inline bool eps_xiaoyu(const T &a, const T &b) {
return b - a > 1e-10 ? 1 : 0;
}
string x, y;
bool solve(int t, int cntx, int cnty) {
if (cntx == 0 && cnty == 0) return 1;
if (cntx) {
if (x[t] < '4') {
int m = t;
for (int i = 0; i < cntx; i++) y[m++] = '4';
for (int i = 0; i < cnty; i++) y[m++] = '7';
return 1;
} else if (x[t] == '4' && solve(t + 1, cntx - 1, cnty)) {
y[t] = '4';
return 1;
}
}
if (cnty) {
if (x[t] < '7') {
int m = t;
y[m++] = '7';
cnty--;
for (int i = 0; i < cntx; i++) y[m++] = '4';
for (int i = 0; i < cnty; i++) y[m++] = '7';
return 1;
} else if (x[t] == '7' && solve(t + 1, cntx, cnty - 1)) {
y[t] = '7';
return 1;
}
}
return 0;
}
int main() {
cin >> x;
int len = x.length();
int tt = len % 2;
if (tt) x = "0" + x;
while (true) {
y = x;
int len = x.length() / 2;
if (solve(0, len, len)) {
cout << y << endl;
return 0;
}
x = "00" + x;
}
return 0;
}
|
#include <bits/stdc++.h>
const int inf = 0x3f3f3f3f;
const int Maxn = 100005;
using namespace std;
int read() {
int x = 0, f = 1;
char s = getchar();
while (s < '0' || s > '9') {
if (s == '-') f = -1;
s = getchar();
}
while (s >= '0' && s <= '9') {
x = x * 10 + s - '0';
s = getchar();
}
return x * f;
}
char s[Maxn];
int len;
void dfs(int x) {
int a = s[x] - '0' + 1;
s[x] = a + '0';
if (a > 7)
dfs(x - 1);
else
return;
}
int main() {
cin >> s + 1;
len = strlen(s + 1);
int a = 0, b = 0;
if (len % 2 == 1) {
for (int i = 1; i <= len / 2 + 1; i++) printf("4");
for (int i = 1; i <= len / 2 + 1; i++) printf("7");
} else {
for (int i = 1; i <= len; i++) {
if (s[i] > '7') {
dfs(i - 1);
break;
}
if (s[i] > '4' && s[i] < '7') break;
if (s[i] >= '0' && s[i] < '4') break;
}
if (s[1] > '7') {
for (int i = 1; i <= len / 2 + 1; i++) printf("4");
for (int i = 1; i <= len / 2 + 1; i++) printf("7");
} else {
int s4 = 0, s7 = 0, pos;
for (int i = 1; i <= len; i++) {
pos = i;
if (s[i] > '4' && s[i] < '7') {
s[i] = '7';
break;
}
if (s[i] >= '0' && s[i] < '4') {
s[i] = '4';
break;
}
}
for (int i = 1; i <= pos; i++)
if (s[i] == '7') s7++;
if (s7 > len / 2) {
bool flag = 0;
int zz = s7;
int zk = pos;
for (int i = zk; i >= 1; i--) {
if (s[i] == '4') {
s[i] = '7';
pos = i;
if (zz + 1 <= len / 2) {
flag = 1;
break;
}
} else
zz--;
}
if (!flag) {
for (int i = 1; i <= len / 2 + 1; i++) printf("4");
for (int i = 1; i <= len / 2 + 1; i++) printf("7");
return 0;
}
}
s7 = 0;
for (int i = 1; i <= pos; i++) {
if (s[i] == '4') s4++;
if (s[i] == '7') s7++;
if (s4 <= len / 2)
printf("%c", s[i]);
else
printf("7");
}
for (int i = s4 + 1; i <= len / 2; i++) printf("4");
for (int i = s7 + 1; i <= len / 2; i++) printf("7");
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
bool isPrime(long long n) {
if (n <= 1) return false;
for (int i = 2; i <= sqrt(n); i++)
if (n % i == 0) return false;
return true;
}
long long factorial(long long n) {
if (n == 0)
return 1;
else
return n * factorial(n - 1);
}
bool primeFactors(int n, int l, int r, bool notFound) {
for (int i = l; i <= r; i++) {
if (i == 1) i++;
if (n % i == 0) {
cout << i << " ";
notFound = false;
}
while (n % i == 0) {
n = n / i;
}
}
return notFound;
}
bool IsInBinarySequence(long long number) {
long long numbertocheck = 1;
do {
if (number == numbertocheck) return true;
numbertocheck *= 2;
} while (numbertocheck <= number);
return false;
}
long long nextPowerOf2(long long n) {
if (n && !(n & (n - 1))) return n;
long long cnt = 0;
while (n != 0) {
n >>= 1;
cnt++;
}
long long x = 1;
x = x << cnt;
return x;
}
long long highestPowerof2(long long n) {
long long res = 0;
for (long long i = n; i >= 1; i--) {
if ((i & (i - 1)) == 0) {
res = i;
break;
}
}
return res;
}
long long fib(long long n) {
if (n <= 1) return 1;
return fib(n - 1) + fib(n - 2);
}
long long binets_formula(long long n) {
double sqrt5 = sqrt(5);
int F_n = (pow((1 + sqrt5), n) - pow((1 - sqrt5), n)) / (pow(2, n) * sqrt5);
return F_n;
}
void first50fib() {
long long arr[] = {
1, 1, 2, 3, 5, 8,
13, 21, 34, 55, 89, 144,
233, 377, 610, 987, 1597, 2584,
4181, 6765, 10946, 17711, 28657, 46368,
75025, 121393, 196418, 317811, 514229, 832040,
1346269, 2178309, 3524578, 5702887, 9227465, 14930352,
24157817, 39088169, 63245986, 102334155, 165580141, 267914296,
433494437, 701408733, 1134903170, 1836311903, 2971215073, 4807526976,
7778742049, 12586269025, 20365011074};
}
int binarySearch(int a[], int first, int last, int search_num) {
int middle;
if (last >= first) {
middle = (first + last) / 2;
if (a[middle] == search_num) {
return middle + 1;
} else if (a[middle] < search_num) {
return binarySearch(a, middle + 1, last, search_num);
} else {
return binarySearch(a, first, middle - 1, search_num);
}
}
return -1;
}
void factorize(long long n) {
int count = 0;
while (!(n % 2)) {
n /= 2;
count++;
}
if (count) cout << 2 << "^" << count << endl;
for (long long i = 3; i <= sqrt(n); i += 2) {
count = 0;
while (n % i == 0) {
count++;
n = n / i;
}
if (count) cout << i << "^" << count << endl;
}
if (n > 2) cout << n << "^" << 1 << endl;
}
void primeFactors(long long num) {
long long fac = 2;
while (num > 1) {
if (num % fac == 0) {
cout << "(" << fac << "^";
num /= fac;
long long pow = 1;
while (num % fac == 0) {
num /= fac;
pow++;
}
cout << pow;
if (num != 1) cout << ")*";
} else {
fac++;
}
}
}
bool onePrimeFactor(long long num) {
long long fac = 2;
int cnt = 0;
while (num > 1) {
if (num % fac == 0) {
cnt++;
while (num % fac == 0) num /= fac;
} else {
fac++;
}
if (cnt >= 2) {
return false;
}
}
return true;
}
bool isPerfect(long long d) {
double temp = d;
d = sqrt(d);
temp = sqrt(temp);
if (temp == d) return true;
return false;
}
void sort(string s[], int n) {
for (int i = 1; i < n; i++) {
string temp = s[i];
int j = i - 1;
while (j >= 0 && temp.length() < s[j].length()) {
s[j + 1] = s[j];
j--;
}
s[j + 1] = temp;
}
}
bool IsPowerOfTwo(long long x) { return (x & (x - 1)) == 0; }
int binarySearchCount(int arr[], int n, int key) {
int left = 0, right = n;
int mid;
while (left < right) {
mid = (right + left) >> 1;
if (arr[mid] == key) {
while (mid + 1 < n && arr[mid + 1] == key) mid++;
break;
} else if (arr[mid] > key)
right = mid;
else
left = mid + 1;
}
while (mid > -1 && arr[mid] > key) mid--;
return mid + 1;
}
bool is(int x, int y) {
set<int> s;
if (x < 10000) {
s.insert(0);
}
if (y < 10000) {
s.insert(0);
}
while (x > 0) {
int d = x % 10;
s.insert(d);
x /= 10;
}
while (y > 0) {
int d = y % 10;
s.insert(d);
y /= 10;
}
return s.size() == 10;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
long long i, n;
set<long long> k;
string s[] = {"47", "4477", "444777", "44447777", "4444477777"};
for (i = 0; i < 5; i++) {
do {
k.insert(stoll(s[i]));
} while (next_permutation(s[i].begin(), s[i].end()));
}
cin >> n;
cout << *k.lower_bound(n);
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100005];
int sum[100005], a[100005], b[100005];
int big, n, seven, four, i;
void Print(int n) {
if (n & 1) ++n;
for (int i = 1; i <= n / 2; i++) putchar('4');
for (int i = 1; i <= n / 2; i++) putchar('7');
exit(0);
}
void Write() {
for (int i = 1; i <= n; i++) printf("%d", b[i]);
exit(0);
}
int main() {
scanf("%s", s + 1);
n = strlen(s + 1);
if (n & 1) Print(n);
for (i = 1; i <= n; i++) a[i] = s[i] - '0';
for (i = 1; i <= n; i++)
if (a[i] != 7) break;
if (i <= n && a[i] > 7) Print(++n);
for (i = 1; i <= n; i++)
if (!big) {
if (a[i] <= 4)
b[i] = 4, big = (a[i] < 4);
else if (a[i] <= 7)
b[i] = 7, big = (a[i] < 7);
else {
for (--i; b[i] != 4; i--)
;
b[i] = 7;
for (++i; i <= n; i++) b[i] = 4;
break;
}
} else
b[i] = 4;
for (i = 1; i <= n; i++) four += b[i] == 4, seven += b[i] == 7;
if (four == seven) Write();
if (four > seven) {
for (i = n; i && four != seven; i--)
if (b[i] == 4) b[i] = 7, four--, seven++;
Write();
}
for (i = 1; i <= n; i++) sum[i] = sum[i - 1] + (b[i] == 4);
for (i = n; i; i--)
if (b[i] == 4 && sum[i - 1] + (n - i) >= n / 2) {
b[i] = 7;
seven++;
four--;
for (++i; i <= n && seven != four; i++)
if (b[i] == 7) b[i] = 4, seven--, four++;
Write();
}
Print(n + 1);
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100555];
int main() {
int n, i, j, b4, b7;
gets(s);
n = strlen(s);
if (n % 2 == 1) {
for (i = 0; i < (n + 1) / 2; i++) printf("4");
for (i = 0; i < (n + 1) / 2; i++) printf("7");
return 0;
}
i = 0;
b4 = 0;
b7 = 0;
while (i < n && (s[i] == '4' || s[i] == '7')) {
if (s[i] == '4')
b4++;
else
b7++;
i++;
}
if (i == n && b4 == b7) {
for (i = 0; i < n; i++) printf("%c", s[i]);
return 0;
}
if (i == n) {
i--;
if (s[i] == '7') {
s[i] = '8';
b7--;
}
if (s[i] == '4') {
s[i] = '5';
b4--;
}
}
if (s[i] > '7') {
j = i - 1;
while (j >= 0 && s[j] == '7') {
b7--;
j--;
}
if (j < 0) {
for (i = 0; i < (n + 2) / 2; i++) printf("4");
for (i = 0; i < (n + 2) / 2; i++) printf("7");
return 0;
}
s[j] = '7';
b7++;
b4--;
} else if (s[i] > '4') {
s[i] = '7';
b7++;
j = i;
} else {
s[i] = '4';
b4++;
j = i;
}
while (n - 1 - j < abs(b4 - b7)) {
while (j >= 0 && s[j] == '7') {
b7--;
j--;
}
if (j < 0) {
for (i = 0; i < (n + 2) / 2; i++) printf("4");
for (i = 0; i < (n + 2) / 2; i++) printf("7");
return 0;
}
s[j] = '7';
b7++;
b4--;
}
b4 = 0;
b7 = 0;
for (i = 0; i <= j; i++) {
printf("%c", s[i]);
if (s[i] == '4')
b4++;
else
b7++;
}
for (i = 0; i < (n / 2) - b4; i++) printf("4");
for (i = 0; i < (n / 2) - b7; i++) printf("7");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long next(long long n) {
if (n % 10 < 4)
return n / 10 * 10 + 4;
else if (n % 10 < 7)
return n / 10 * 10 + 7;
else
return next(n / 10) * 10 + 4;
}
bool good(long long n, int a, int b) {
if (n == 0) return (a == b);
if (n % 10 == 4)
a++;
else if (n % 10 == 7)
b++;
else
return false;
return good(n / 10, a, b);
}
int main() {
long long n;
cin >> n;
while (!good(n, 0, 0)) n = next(n);
cout << n;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
void init() {
cin.tie(0);
cin.sync_with_stdio(0);
}
long long n, lst = 1e10;
void lucky(long long a, int s, int f) {
if (a > 1e10) return;
if (a >= n && s == f) lst = min(lst, a);
lucky(a * 10 + 4, s, f + 1);
lucky(a * 10 + 7, s + 1, f);
}
void luk(int s, int f, int n) {
if (s == f && n == 0) return;
}
int main() {
init();
cin >> n;
lucky(0, 0, 0);
cout << lst;
}
|
#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T modinv(T a, T n) {
T i = n, v = 0, d = 1;
while (a > 0) {
T t = i / a, x = a;
a = i % x;
i = x;
x = d;
d = v - t * x;
v = x;
}
return (v + n) % n;
}
long long modpow(long long n, long long k, long long mod) {
long long ans = 1;
while (k > 0) {
if (k & 1) ans = (ans * n) % mod;
k >>= 1;
n = (n * n) % mod;
}
return ans % mod;
}
template <class T>
struct Fraction {
T a, b;
Fraction(T a = 0, T b = 1);
string toString();
};
template <class T>
Fraction<T>::Fraction(T a, T b) {
T d = GCD(a, b);
a /= d;
b /= d;
if (b < 0) a = -a, b = -b;
this->a = a;
this->b = b;
}
template <class T>
string Fraction<T>::toString() {
ostringstream sout;
sout << a << "/" << b;
return sout.str();
}
template <class T>
Fraction<T> operator+(Fraction<T> p, Fraction<T> q) {
return Fraction<T>(p.a * q.b + q.a * p.b, p.b * q.b);
}
template <class T>
Fraction<T> operator-(Fraction<T> p, Fraction<T> q) {
return Fraction<T>(p.a * q.b - q.a * p.b, p.b * q.b);
}
template <class T>
Fraction<T> operator*(Fraction<T> p, Fraction<T> q) {
return Fraction<T>(p.a * q.a, p.b * q.b);
}
template <class T>
Fraction<T> operator/(Fraction<T> p, Fraction<T> q) {
return Fraction<T>(p.a * q.b, p.b * q.a);
}
template <class T>
string str(T Number) {
string Result;
ostringstream convert;
convert << Number;
Result = convert.str();
return Result;
}
int StringToNumber(const string &Text) {
istringstream ss(Text);
int result;
return ss >> result ? result : 0;
}
template <class T>
inline vector<pair<T, int> > FACTORISE(T n) {
vector<pair<T, int> > R;
for (T i = 2; n > 1;) {
if (n % i == 0) {
int C = 0;
for (; n % i == 0; C++, n /= i)
;
R.push_back(make_pair(i, C));
}
i++;
if (i > n / i) i = n;
}
if (n > 1) R.push_back(make_pair(n, 1));
return R;
}
template <class T>
inline T TOTIENT(T n) {
vector<pair<T, int> > R = FACTORISE(n);
T r = n;
for (int i = 0; i < R.size(); i++) r = r / R[i].first * (R[i].first - 1);
return r;
}
template <class T>
inline T gcd(T a, T b) {
return b ? gcd(b, a % b) : a;
}
double rnd(float d) { return floor(d + 0.49); }
char s[100005], ans[100005];
int n;
void go(int m) {
for (int i = 0; i < m / 2; i++) ans[i] = '4';
for (int i = m / 2; i < m; i++) ans[i] = '7';
ans[m] = 0;
}
bool solve(int i, int c4, bool greater) {
if (i == n) return c4 == 0;
if (greater) {
if (c4) {
ans[i] = '4';
return solve(i + 1, c4 - 1, true);
} else {
ans[i] = '7';
return solve(i + 1, c4, true);
}
} else {
if (s[i] < '4') {
if (c4) {
ans[i] = '4';
return solve(i + 1, c4 - 1, true);
} else {
ans[i] = '7';
return solve(i + 1, c4, true);
}
} else if (s[i] == '4') {
if (c4) {
ans[i] = '4';
if (solve(i + 1, c4 - 1, false)) return true;
}
ans[i] = '7';
return solve(i + 1, c4, true);
} else if (s[i] <= '7') {
ans[i] = '7';
return solve(i + 1, c4, s[i] < '7');
}
return false;
}
}
int main() {
scanf("%s", s);
n = strlen(s);
if (n % 2 == 0) {
if (!solve(0, n / 2, false))
go(n + 2);
else
ans[n] = 0;
} else {
go(n + 1);
}
printf("%s\n", ans);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
char a[MAXN], ans[MAXN];
int n;
int main() {
cin >> (a + 1);
int n = strlen(a + 1);
if (n & 1) {
ODD_N:
for (int i = 1; i <= n / 2 + 1; i++) {
putchar('4');
}
for (int i = 1; i <= n / 2 + 1; i++) {
putchar('7');
}
putchar('\n');
} else {
int lead4 = 0, lead7 = 0, now = 1;
while (now <= n) {
if (a[now] < '4') {
break;
} else if (a[now] == '4' && lead4 < n / 2) {
ans[now] = '4';
lead4++;
now++;
} else if (a[now] < '7' && lead7 < n / 2) {
ans[now] = '7';
lead7++;
break;
} else if (a[now] == '7' && lead7 < n / 2) {
ans[now] = '7';
lead7++;
now++;
} else {
goto TRY_LAST_USE_7;
}
}
if (false) {
TRY_LAST_USE_7:
while (--now) {
if (ans[now] == '4') {
lead4--;
} else {
lead7--;
}
if (ans[now] < '7' && lead7 < n / 2) {
ans[now] = '7';
lead7++;
goto OUTPUT;
}
}
goto ODD_N;
}
OUTPUT:
for (int i = 1; i <= lead4 + lead7; i++) {
putchar(ans[i]);
}
for (int i = 1; i <= n / 2 - lead4; i++) {
putchar('4');
}
for (int i = 1; i <= n / 2 - lead7; i++) {
putchar('7');
}
putchar('\n');
}
}
|
#include <bits/stdc++.h>
using namespace std;
long long digits(long long n) {
long long count = 0;
while (n > 0) {
count++;
n /= 10;
}
return count;
}
int main() {
long long n;
cin >> n;
long long nd = 0;
string r;
string s;
nd = digits(n);
if (nd % 2 == 1) {
for (long long i = 0; i < (nd + 1) / 2; i++) cout << 4;
for (long long i = 0; i < (nd + 1) / 2; i++) cout << 7;
return 0;
}
for (long long i = 0; i < nd / 2; i++) r += '7';
for (long long i = 0; i < nd / 2; i++) r += '4';
if (stoll(r) < n) {
for (long long i = 0; i < (nd + 2) / 2; i++) cout << 4;
for (long long i = 0; i < (nd + 2) / 2; i++) cout << 7;
return 0;
} else {
for (long long i = 0; i < nd / 2; i++) s += '4';
for (long long i = 0; i < nd / 2; i++) s += '7';
string temp = s;
while (stoll(s) < n) {
next_permutation(s.begin(), s.end());
if (s == temp) break;
}
cout << s;
}
}
|
#include <bits/stdc++.h>
int main(int argc, char *argv[]) {
int i, k, sev_q, four_q, last_four_idx, four_c = 0, sev_c = 0, last_idx;
char *in = (char *)calloc(100000 + 1 + 2, 1);
scanf("%s", in + 1);
sev_q = in[1] == '7';
four_q = in[1] == '4';
if (four_q) {
last_four_idx = 1;
four_c++;
} else if (sev_q) {
last_four_idx = 0;
sev_c++;
} else if (in[1] < '4') {
in[1] = '4';
four_c++;
} else if (in[1] > '4' && in[1] < '7') {
in[1] = '7';
sev_c++;
} else if (in[1] > '7') {
in[0] = '4';
in[1] = '4';
four_c += 2;
}
i = 2;
while (in[i]) {
if (sev_q) {
sev_q = 0;
if (in[i] < '4') {
in[i] = '4';
four_c++;
} else if (in[i] == '4') {
four_q = 1;
four_c++;
} else if (in[i] > '4' && in[i] < '7') {
in[i] = '7';
sev_c++;
} else if (in[i] > '7') {
if (last_four_idx == 0) {
in[last_four_idx] = '4';
four_c++;
} else {
in[last_four_idx] = '7';
sev_c++;
four_c--;
}
sev_c -= i - 1 - last_four_idx;
four_c += i - last_four_idx;
for (k = last_four_idx + 1; k <= i; k++) in[k] = '4';
} else {
sev_q = 1;
sev_c++;
}
} else if (four_q) {
four_q = 0;
if (in[i] < '4') {
in[i] = '4';
four_c++;
} else if (in[i] > '4' && in[i] < '7') {
in[i] = '7';
sev_c++;
} else if (in[i] > '7') {
in[i] = '4';
in[i - 1] = '7';
sev_c++;
} else if (in[i] == '7') {
sev_q = 1;
last_four_idx = i - 1;
sev_c++;
} else {
four_q = 1;
four_c++;
}
} else {
size_t len = strlen(in + i);
memset(in + i, '4', len);
four_c += len;
i += len;
break;
}
i++;
}
in = in[0] == '\0' ? in + 1 : in;
i--;
last_idx = i;
if ((four_c + sev_c) % 2 != 0) {
int seq = (four_c + sev_c) / 2 + 1;
memset(in, '4', seq);
memset(in + seq, '7', seq);
} else if (sev_c > four_c) {
while (i >= 0) {
if (in[i] == '7') {
int k = i;
while (i >= 0 && in[i] == '7') i--;
if (i < 0) {
int seq = (four_c + sev_c) / 2 + 1;
memset(in, '4', seq);
memset(in + seq, '7', seq);
break;
} else {
in[i] = '7';
sev_c++;
four_c--;
memset(in + i + 1, '4', k - i);
four_c += k - i;
sev_c -= k - i;
i++;
}
if (sev_c < four_c) {
i = last_idx;
while (i >= 0) {
if (in[i] == '4') {
in[i] = '7';
four_c--;
sev_c++;
}
if (four_c == sev_c) break;
i--;
}
}
}
if (four_c == sev_c) break;
i--;
}
} else if (four_c > sev_c) {
while (i >= 0) {
if (in[i] == '4') {
in[i] = '7';
four_c--;
sev_c++;
}
if (four_c == sev_c) break;
i--;
}
}
printf("%s", in);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
long long n;
vector<long long> v;
int32_t main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
;
string s = "47";
long long t = 2;
while (t--) {
next_permutation(s.begin(), s.end());
stringstream geek(s);
long long x = 0;
geek >> x;
v.push_back(x);
}
s = "4477";
t = 6;
while (t--) {
next_permutation(s.begin(), s.end());
stringstream geek(s);
long long x = 0;
geek >> x;
v.push_back(x);
}
s = "444777";
t = 20;
while (t--) {
next_permutation(s.begin(), s.end());
stringstream geek(s);
long long x = 0;
geek >> x;
v.push_back(x);
}
s = "44447777";
t = 70;
while (t--) {
next_permutation(s.begin(), s.end());
stringstream geek(s);
long long x = 0;
geek >> x;
v.push_back(x);
}
long long y = 4444477777;
v.push_back(y);
sort(v.begin(), v.end());
long long n;
cin >> n;
auto p = lower_bound(v.begin(), v.end(), n);
long long xx = p - v.begin();
cout << v[xx] << " ";
}
|
#include <bits/stdc++.h>
using namespace std;
int a[100002], c[100002];
int main() {
int i, j, k1 = 0, k2 = 0, n;
a[0] = 0;
string s;
cin >> s;
n = s.length();
if (n % 2 == 1) {
for (i = 1; i <= (n + 1) / 2; i++) cout << 4;
for (i = 1; i <= (n + 1) / 2; i++) cout << 7;
} else {
for (i = 1; i <= n; i++) {
a[i] = (int)(s[i - 1] - 48);
c[i] = a[i];
}
for (i = n; i >= 1; i--)
if (a[i] > 7) {
a[i] = 4;
a[i - 1]++;
} else if (a[i] > 4) {
a[i] = 7;
} else
a[i] = 4;
for (i = 1; i <= n; i++)
if (a[i] > c[i]) {
for (j = i + 1; j <= n; j++) a[j] = 4;
break;
}
if (a[0] > 0) {
for (i = 1; i <= (n + 2) / 2; i++) cout << 4;
for (i = 1; i <= (n + 2) / 2; i++) cout << 7;
} else {
for (i = 1; i <= n; i++)
if (a[i] == 4)
k1++;
else
k2++;
if (k1 > k2) {
i = n;
while (k1 > k2) {
if (a[i] == 4) {
a[i] = 7;
k1--;
k2++;
}
i--;
}
for (i = 1; i <= n; i++) cout << a[i];
} else if (k1 == k2)
for (i = 1; i <= n; i++) cout << a[i];
else {
int p = 0, p1 = 0, m = k2 - k1 + 2;
for (i = n; i >= 1; i--) {
if (m <= 0) {
break;
} else if (a[i] == 7)
m -= 2;
}
for (j = i; j >= 1; j--)
if (a[j] == 4) {
a[j] = 7;
for (i = j + 1; i <= n; i++) a[i] = 4;
break;
}
if (j != 0) {
k1 = 0;
k2 = 0;
for (i = 1; i <= n; i++)
if (a[i] == 4)
k1++;
else
k2++;
i = n;
while (k1 > k2) {
if (a[i] == 4) {
a[i] = 7;
k1--;
k2++;
}
i--;
}
for (i = 1; i <= n; i++) cout << a[i];
} else {
for (i = 1; i <= (n + 2) / 2; i++) cout << 4;
for (i = 1; i <= (n + 2) / 2; i++) cout << 7;
}
}
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
int x;
cin >> x;
int n = 11;
long long res = 1e15;
for (int mask = 0; mask < (1 << n); mask++) {
long long num = 0;
int cnt4 = 0, cnt7 = 0;
for (int i = n - 1; i >= 0; i--) {
if (mask & (1 << i)) {
num = num * 10 + 7;
cnt7++;
} else {
num = num * 10 + 4;
cnt4++;
}
if (cnt4 == cnt7 && num >= x) {
res = min(res, num);
}
}
}
cout << res << '\n';
}
|
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
string s;
cin >> s;
int n = s.size();
if (n % 2 == 1) {
for (int i = 0; i < n + 1; ++i) {
cout << (i < (n + 1) / 2 ? 4 : 7);
}
cout << endl;
return 0;
}
int seven = 0, four = 0;
for (int i = 0; i < n; ++i) {
if (s[i] == '4') {
four++;
}
if (s[i] == '7') {
seven++;
}
}
if (seven == four && seven + four == n) {
cout << s << endl;
return 0;
}
for (int i = n - 1; i >= 0; --i) {
if (s[i] == '4') {
four--;
}
if (s[i] == '7') {
seven--;
}
if (seven + four != i) {
continue;
}
if (seven > n / 2 || four > n / 2) {
continue;
}
if (s[i] < '4' && n / 2 - four > 0) {
s[i] = '4';
four++;
int x = i + 1;
while (four < n / 2) {
s[x++] = '4';
four++;
}
while (seven < n / 2) {
s[x++] = '7';
seven++;
}
cout << s << endl;
return 0;
}
if (s[i] < '7' && n / 2 - seven > 0) {
s[i] = '7';
seven++;
int x = i + 1;
while (four < n / 2) {
s[x++] = '4';
four++;
}
while (seven < n / 2) {
s[x++] = '7';
seven++;
}
cout << s << endl;
return 0;
}
}
for (int i = 0; i < n + 2; ++i) {
cout << (i < (n + 2) / 2 ? 4 : 7);
}
cout << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
string s, ans;
int n;
bool solve(int p, int n4, int n7, bool ok) {
if (p == n) return 1;
if (ok) {
for (int i = 0; i < n7; ++i) ans += '7';
for (int i = 0; i < n4; ++i) ans += '4';
return 1;
}
if (n4 >= 1 && s[p] <= '4' && solve(p + 1, n4 - 1, n7, s[p] < '4')) {
ans += '4';
return 1;
} else if (n7 >= 1 && s[p] <= '7' && solve(p + 1, n4, n7 - 1, s[p] < '7')) {
ans += '7';
return 1;
}
return false;
}
int main() {
while (cin >> s) {
n = s.size();
ans.clear();
if (n % 2 == 0 && solve(0, n / 2, n / 2, false)) {
reverse(ans.begin(), ans.end());
cout << ans << endl;
} else {
if (n % 2 == 0)
n += 2;
else
++n;
for (int i = 0; i < n / 2; ++i) cout << 4;
for (int i = 0; i < n / 2; ++i) cout << 7;
cout << endl;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAX_K = 100000;
char s[MAX_K + 4];
int ds[MAX_K + 4];
int fillds(int ds[], int p, int n4, int n7) {
while (n4--) ds[p++] = 4;
while (n7--) ds[p++] = 7;
return p;
}
int rollback(int ds[], int p, int h, int n4, int n7) {
p--;
while (p >= 0) {
if (ds[p] == 4) {
n4--;
if (n7 < h) break;
p--;
} else {
n7--;
p--;
}
}
if (p < 0) return fillds(ds, 0, h + 1, h + 1);
ds[p++] = 7, n7++;
return fillds(ds, p, h - n4, h - n7);
}
int main() {
scanf("%s", s);
int k = strlen(s);
if (k & 1) {
int h = (k + 1) / 2;
k = fillds(ds, 0, h, h);
} else {
int h = k / 2;
int n4 = 0, n7 = 0, p = 0;
while (p >= 0 && p < k) {
if (s[p] < '4')
p = fillds(ds, p, h - n4, h - n7);
else if (s[p] == '4') {
if (n4 < h)
ds[p++] = 4, n4++;
else
p = fillds(ds, p, 0, h - n7);
} else if (s[p] < '7') {
if (n7 < h) {
ds[p++] = 7, n7++;
p = fillds(ds, p, h - n4, h - n7);
} else
k = p = rollback(ds, p, h, n4, n7);
} else if (s[p] == '7') {
if (n7 < h)
ds[p++] = 7, n7++;
else
k = p = rollback(ds, p, h, n4, n7);
} else
k = p = rollback(ds, p, h, n4, n7);
}
}
for (int i = 0; i < k; i++) putchar(ds[i] + '0');
putchar('\n');
return 0;
}
|
#include <bits/stdc++.h>
char s[100010];
char pp[100010];
bool dfs(int pos, int n4, int n7, bool doing) {
if (n4 + n7 == 0) return true;
if (!doing) {
if (n4) {
pp[pos] = '4';
return dfs(pos + 1, n4 - 1, n7, doing);
} else {
pp[pos] = '7';
return dfs(pos + 1, n4, n7 - 1, doing);
}
} else {
if (s[pos] <= '4' && n4) {
pp[pos] = '4';
if (dfs(pos + 1, n4 - 1, n7, doing && s[pos] == '4')) return true;
}
if (s[pos] <= '7' && n7) {
pp[pos] = '7';
if (dfs(pos + 1, n4, n7 - 1, doing && s[pos] == '7')) return true;
}
}
return false;
}
int main() {
scanf("%s", s);
int len = strlen(s);
if ((len & 1) || !dfs(0, len / 2, len / 2, true)) {
if (len & 1)
len++;
else
len += 2;
for (int i = 0; i < len / 2; i++) printf("4");
for (int i = 0; i < len / 2; i++) printf("7");
printf("\n");
} else
printf("%s\n", pp);
return 0;
}
|
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
string s;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
cin >> s;
if (s.size() % 2 == 1) {
int p = s.size() + 1;
for (int j = 1; j <= p / 2; ++j) cout << 4;
for (int j = 1; j <= p / 2; ++j) cout << 7;
return 0;
}
int p = s.size();
int c = 0;
for (int j = 1; j <= p / 2; ++j)
if (s[j - 1] - '0' > 7) {
c = 1;
break;
} else if (s[j - 1] - '0' < 7) {
c = -1;
break;
}
if (c == 0)
for (int j = p / 2 + 1; j <= p; ++j)
if (s[j - 1] - '0' > 4) {
c = 1;
break;
} else if (s[j - 1] - '0' < 4) {
c = -1;
break;
}
if (c == 1) {
p += 2;
for (int j = 1; j <= p / 2; ++j) cout << 4;
for (int j = 1; j <= p / 2; ++j) cout << 7;
return 0;
}
string sol;
int nr4 = 0, nr7 = 0;
int n = s.size();
for (int i = 0; i < s.size(); ++i) {
if (s[i] < '4') {
sol += '4', ++nr4;
break;
} else if (s[i] == '4') {
if (nr4 < n / 2)
sol += '4', ++nr4;
else {
sol += '7', ++nr7;
break;
}
} else if (s[i] < '7') {
sol += '7';
++nr7;
break;
} else if (s[i] == '7') {
if (nr7 < n / 2) {
sol += '7';
++nr7;
} else {
while (1) {
if (sol.back() == '4') {
--nr4, sol.pop_back();
if (nr7 < n / 2) {
sol += '7', ++nr7;
break;
}
} else
--nr7, sol.pop_back();
}
break;
}
} else {
while (sol.back() == '7') sol.pop_back(), --nr7;
if (!sol.empty()) sol.pop_back(), --nr4;
sol += '7', ++nr7;
break;
}
}
cout << sol;
for (int i = nr4 + 1; i <= n / 2; ++i) cout << 4;
for (int i = nr7 + 1; i <= n / 2; ++i) cout << 7;
return 0;
}
|
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
;
string t;
cin >> t;
int n = t.length();
if (n & 1) {
for (int i = 0; i < (int)(n + 1) / 2; ++i) {
cout << 4;
}
for (int i = 0; i < (int)(n + 1) / 2; ++i) {
cout << 7;
}
cout << '\n';
return 0;
}
bool any = false;
int f = 0, s = 0;
string ans(n, 'a');
for (int i = 0; i < (int)n; ++i) {
if (any) {
if (f < n / 2) {
++f;
ans[i] = '4';
} else {
++s;
ans[i] = '7';
}
} else {
if (t[i] > '7' || (t[i] > '4' && s == n / 2)) {
cerr << '[' << "i"
<< " ] = " << (i) << endl;
;
for (int j = (i)-1; j >= (int)0; --j) {
if (ans[j] == '4' && t[j] < '7' && s < n / 2) {
--f;
++s;
ans[j] = '7';
any = true;
i = j;
break;
}
if (ans[j] == '4')
--f;
else
--s;
}
if (!any) {
s = -1, f = -1;
}
} else if (t[i] > '4') {
ans[i] = '7';
++s;
if ('7' > t[i]) any = true;
} else {
char tar = (f == n / 2 ? '7' : '4');
ans[i] = tar;
f += tar == '4';
s += tar == '7';
if (tar > t[i]) any = true;
}
}
}
if (s == n / 2 && f == n / 2) {
cout << ans << '\n';
} else {
for (int i = 0; i < (int)n / 2 + 1; ++i) cout << 4;
for (int i = 0; i < (int)n / 2 + 1; ++i) cout << 7;
cout << '\n';
return 0;
}
}
|
#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
string s;
void answer(string ans) {
if (ans < s || ans.size() % 2) {
int n = ((s.size()) / 2) + 1;
ans = string(n, '4') + string(n, '7');
}
cout << ans << '\n';
exit(0);
}
int main() {
cin >> s;
int n = s.size();
s[n - 1]--;
for (int i = n - 1; i >= 0; --i)
if (s[i] < '0') {
s[i] += 10;
s[i - 1]--;
}
int four_rem = n / 2, seven_rem = n - four_rem;
string ans;
int last_kill = -1;
for (int i = 0; i < n; ++i) {
if (s[i] < '4' && four_rem > 0) {
ans += '4';
--four_rem;
for (int j = i + 1; j < n; ++j)
if (four_rem) {
ans += '4';
--four_rem;
} else {
ans += '7';
--seven_rem;
}
answer(ans);
}
if (s[i] < '7' && seven_rem > 0) {
last_kill = i;
}
if (s[i] == '4') {
if (four_rem == 0) break;
--four_rem;
ans += '4';
} else if (s[i] == '7') {
if (seven_rem == 0) break;
--seven_rem;
ans += '7';
} else {
break;
}
}
if (last_kill == -1) answer("");
while (four_rem-- > 0) ans += '4';
while (seven_rem-- > 0) ans += '7';
for (int i = last_kill; i < n; ++i)
if (ans[i] == '7') {
swap(ans[i], ans[last_kill]);
break;
}
sort(ans.begin() + last_kill + 1, ans.end());
answer(ans);
}
|
#include <bits/stdc++.h>
using namespace std;
inline int in() {
int32_t x;
scanf("%d", &x);
return x;
}
inline long long lin() {
long long x;
scanf("%lld", &x);
return x;
}
char ch[4000010];
inline string get() {
scanf("%s", ch);
return string(ch);
}
inline void read(int *a, int n) {
for (int i = 0; i < n; i++) a[i] = in();
}
template <class blank>
inline void out(blank x) {
cout << x << "\n";
exit(0);
}
template <class blank, class blank2>
inline void smin(blank &a, blank2 b) {
a = a <= b ? a : b;
}
template <class blank, class blank2>
inline void smax(blank &a, blank2 b) {
a = a >= b ? a : b;
}
const int maxn = 4e3 + 10;
const int maxm = 4e6 + 10;
const int maxlg = 22;
const int base = 29;
const int mod = 1e9 + 7;
const long long inf = 1e9 + 10;
const double eps = 1e-4;
const int SQ = 317;
inline bool ok(string &s) {
int cnt[] = {0, 0};
for (int i = 0; i < s.size(); i++) {
if (s[i] != '4' && s[i] != '7') return false;
cnt[(s[i] - '0') / 5]++;
}
return cnt[0] == cnt[1];
}
int pref[maxn][2];
int32_t main() {
string s = get();
int n = (int)s.size();
if (n % 2) {
for (int j = 0; j <= n; j++) cout << (j <= n / 2 ? 4 : 7);
return 0;
}
if (ok(s)) out(s);
for (int i = 0; i < n; i++) {
if (i)
for (int j = 0; j < 2; j++) pref[i][j] = pref[i - 1][j];
if (s[i] == '4')
pref[i][0]++;
else if (s[i] == '7')
pref[i][1]++;
}
for (int i = n - 1; i >= 0; i--) {
if (i == 0 || pref[i - 1][0] + pref[i - 1][1] == i) {
if (s[i] < '4') {
int four = (i ? pref[i - 1][0] : 0) + 1;
int seven = (i ? pref[i - 1][1] : 0);
int fourRight = n / 2 - four;
int sevenRight = n - i - 1 - fourRight;
if (fourRight >= 0 && sevenRight >= 0) {
cout << s.substr(0, i) << '4';
while (fourRight--) cout << 4;
while (sevenRight--) cout << 7;
return 0;
}
}
if (s[i] < '7') {
int four = (i ? pref[i - 1][0] : 0);
int seven = (i ? pref[i - 1][1] : 0) + 1;
int fourRight = n / 2 - four;
int sevenRight = n - i - 1 - fourRight;
if (fourRight >= 0 && sevenRight >= 0) {
cout << s.substr(0, i) << '7';
while (fourRight--) cout << 4;
while (sevenRight--) cout << 7;
return 0;
}
}
}
}
n += 2;
for (int i = 1; i <= n; i++) cout << (i <= n / 2 ? 4 : 7);
}
|
#include <bits/stdc++.h>
using namespace std;
inline int random(int max) {
return int(double(rand()) * max / (RAND_MAX + 1.0));
}
struct edge {
int src, dst, next;
int w;
edge(int src = 0, int dst = 0, int w = 0, int next = -1)
: src(src), dst(dst), w(w), next(next) {}
};
bool operator<(const edge& e, const edge& f) {
return e.w != f.w ? e.w > f.w
: e.src != f.src ? e.src < f.src
: e.dst < f.dst;
}
namespace std {
bool operator<(const complex<double>& a, const complex<double>& b) {
return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b);
}
} // namespace std
int l = 0;
long long ln[500];
void go(long long n, long long f, long long s) {
if (n > 1000000000ll) return;
if (f == s) ln[l++] = n;
go(n * 10 + 4, f + 1, s);
go(n * 10 + 7, f, s + 1);
}
int main() {
long long n;
go(4, 1, 0);
go(7, 0, 1);
ln[l++] = 4444477777ll;
sort(ln, ln + l);
scanf("%I64d", &n);
long long ans = *lower_bound(ln, ln + l, n);
printf("%I64d\n", ans);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int maxN = 1000 * 1000 + 100;
int n;
string s;
char res[maxN];
bool solve(int x, int four, int seven) {
if (x == n) return 1;
if (s[x] > '7') return 0;
if (s[x] == '7')
if (seven == 0)
return 0;
else {
res[x] = '7';
return solve(x + 1, four, seven - 1);
}
if (s[x] > '4')
if (seven == 0)
return 0;
else {
seven--;
res[x] = '7';
for (int i = 0; i < four; i++) res[x + 1 + i] = '4';
for (int i = 0; i < seven; i++) res[x + 1 + four + i] = '7';
return 1;
}
else if (s[x] == '4')
if (four == 0) {
for (int i = x; i < n; i++) res[i] = '7';
return 1;
} else {
int ret = solve(x + 1, four - 1, seven);
if (ret == 0) {
if (seven == 0) return 0;
res[x] = '7';
for (int i = 0; i < four; i++) res[x + 1 + i] = '4';
for (int i = 0; i < seven; i++) res[x + 1 + four + i] = '7';
return 1;
}
res[x] = '4';
return 1;
}
for (int i = 0; i < four; i++) res[x + i] = '4';
for (int i = 0; i < seven; i++) res[x + four + i] = '7';
return 1;
}
int main() {
cin >> s;
n = s.size();
if (n % 2) {
n++;
cout << string(n / 2, '4') << string(n / 2, '7') << endl;
return 0;
}
string great = string(n / 2, '7') + string(n / 2, '4');
if (s == great) {
cout << s << endl;
return 0;
}
if (great < s) {
cout << string(n / 2 + 1, '4') + string(n / 2 + 1, '7') << endl;
return 0;
}
if (!solve(0, n / 2, n / 2))
while (1)
;
for (int i = 0; i < n; i++) cout << res[i];
cout << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
char n[100010];
char a[100010];
int main() {
scanf("%s", n);
int l = strlen(n);
if (l % 2 == 1) {
for (int i = 0; i < (l + 1) / 2; i++) putchar('4');
for (int i = 0; i < (l + 1) / 2; i++) putchar('7');
printf("\n");
return 0;
} else {
int m4 = l / 2;
int m7 = l / 2;
bool eq = true;
memset(a, 0, sizeof(a));
for (int i = 0; i < l; i++) {
if (!eq) {
if (m4 > 0) {
a[i] = '4';
m4--;
} else {
a[i] = '7';
m7--;
}
} else {
if (n[i] <= '4' && m4 > 0) {
a[i] = '4';
m4--;
if (n[i] < '4') eq = false;
} else if (n[i] <= '4' && m4 == 0) {
a[i] = '7';
m4--;
eq = false;
} else if (n[i] <= '7' && m7 > 0) {
a[i] = '7';
m7--;
if (n[i] < '7') eq = false;
} else {
for (i--; i >= 0; i--) {
if (a[i] == '4')
m4++;
else
m7++;
if (a[i] == '4' && m7 > 0) {
a[i] = '7';
m7--;
eq = false;
break;
}
}
if (i == -1) {
for (i = 0; i < l / 2 + 1; i++) a[i] = '4';
for (; i < l + 2; i++) a[i] = '7';
break;
}
}
}
}
printf("%s\n", a);
}
}
|
#include <bits/stdc++.h>
using namespace std;
long long n;
long long mini = 1e12;
void solve(long long lucky = 0, int c = 0) {
if (lucky > 1e11) return;
if (lucky >= n && c == 0) mini = min(mini, lucky);
solve(lucky * 10 + 4, c + 1);
solve(lucky * 10 + 7, c - 1);
}
int main() {
cin >> n;
solve();
cout << mini;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int n = 3000;
bool arr[3002];
int ar[3002];
void prime() {
for (int i = 2; i < n; i += 2) {
arr[i] = 1;
}
arr[2] = 0;
for (int j = 3; j * j < n; j++) {
if (!arr[j])
for (int i = j * j; i < n; i += j) arr[i] = 1;
}
}
void getall(int x) {
ar[6] = 1;
for (int i = 7; i <= x; i++) {
int cntr = 0;
for (int j = 2; j <= i / 2; j++) {
if (!arr[j] && !(i % j)) cntr++;
}
if (cntr == 2) {
ar[i] = ar[i - 1] + 1;
} else
ar[i] = ar[i - 1];
}
}
set<long long> st;
void get(long long s, long long c, int c4, int c7) {
if (s > 4444477777) return;
if ((c4 + c7) % 2 == 0 && c4 == c7) st.insert(s);
if (c4 < 5) get(s + 4 * c, c * 10, c4 + 1, c7);
if (c7 < 5) get(s + 7 * c, c * 10, c4, c7 + 1);
}
int main() {
get(0, 1, 0, 0);
set<long long>::iterator it = st.begin();
long long x;
scanf("%lld", &x);
while (it != st.end() && (*it) < x) {
it++;
}
cout << (*it);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
queue<pair<long long, long long> > v;
int main() {
long long x, val, c;
cin >> x;
v.push(make_pair(0, 0));
while (!v.empty()) {
val = v.front().first;
c = v.front().second;
v.pop();
if (val >= x && c == 0) return cout << val, 0;
v.push(make_pair(val * 10 + 4, c + 1));
v.push(make_pair(val * 10 + 7, c - 1));
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int d2x[] = {1, -1, 0, 0, 1, -1, 1, -1};
int d2y[] = {0, 0, 1, -1, 1, -1, -1, 1};
int d3x[] = {1, -1, 0, 0, 0, 0};
int d3y[] = {0, 0, 1, -1, 0, 0};
int d3z[] = {0, 0, 0, 0, 1, -1};
struct edge {
int from, to, w;
edge(int from, int to, int w) : from(from), to(to), w(w) {}
bool operator<(const edge& e) const { return w > e.w; }
};
const double EPS = (1e-9);
string n, res;
bool m = false;
int cnt = 0;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
;
cin >> n;
if (n.size() % 2 == 1) {
for (int i = 0; i < ((int)((n).size())) / 2 + 1; i++) cout << "4";
for (int i = 0; i < ((int)((n).size())) / 2 + 1; i++) cout << "7";
} else {
for (int i = 0; i < ((int)((n).size())) / 2; i++) {
if (n[i] < '7') break;
if (n[i] > '7') {
m = true;
break;
} else if (n[i] == '7')
++cnt;
}
if (!m && cnt == ((int)((n).size())) / 2) {
for (int i = 0; i < ((int)((n).size())) / 2; i++) {
if (n[i + ((int)((n).size())) / 2] < '4') break;
if (n[i + ((int)((n).size())) / 2] > '4') {
m = true;
break;
}
}
}
if (m) {
for (int i = 0; i < ((int)((n).size())) / 2 + 1; i++) cout << "4";
for (int i = 0; i < ((int)((n).size())) / 2 + 1; i++) cout << "7";
} else {
int sCount = ((int)((n).size())) / 2;
int fCount = ((int)((n).size())) / 2;
for (int i = 0; i < ((int)((n).size())); i++) {
if (n[i] <= '4' && fCount) {
if (n[i] < '4') {
while (res.size() < ((int)((n).size()))) {
if (fCount) {
res += "4";
--fCount;
} else {
res += "7";
}
}
break;
} else {
res += "4";
--fCount;
}
} else if (n[i] <= '4' && fCount == 0) {
while (res.size() < ((int)((n).size()))) res += "7";
break;
} else if (n[i] > '4' && n[i] <= '7' && sCount) {
res += "7";
--sCount;
if (n[i] < '7') {
while (res.size() < ((int)((n).size()))) {
if (fCount) {
res += "4";
--fCount;
} else {
res += "7";
}
}
break;
}
} else if (n[i] > '4') {
bool flag = false;
for (int j = ((int)((res).size())) - 1; j >= 0; --j) {
if (res[j] == '7')
flag = true;
else if (res[j] == '4' && sCount) {
res[j] = '7';
--sCount;
++fCount;
for (int k = j + 1; k < i; ++k) {
if (fCount) {
if (res[k] == '7') {
res[k] = '4';
++sCount;
--fCount;
}
} else {
break;
}
}
break;
} else if (res[j] == '4' && flag) {
res[j] = '7';
--sCount;
++fCount;
for (int e = j + 1; e < i; ++e) {
if (res[e] == '7' && fCount) {
--fCount;
res[e] = '4';
}
}
break;
} else {
if (res[j] == '4')
++fCount;
else
++sCount;
res.resize(res.size() - 1);
}
}
while (res.size() < ((int)((n).size()))) {
if (fCount) {
res += "4";
--fCount;
} else {
res += "7";
}
}
break;
}
}
cout << res;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e9 + 7;
const int N = 2e5 + 10;
void refrain(string &str) {
if (str.length() % 2 == 1) {
int o = (str.length() + 1) / 2;
str = string(o, '4') + string(o, '7');
return;
}
int l = str.length();
for (int i = 0; i < l; i++) {
if (str[i] == '4' || str[i] == '7') continue;
if (str[i] > '7') {
int c = 1;
str[i] = '4';
for (int j = i + 1; j < l; j++) str[i] = '4';
for (int j = i - 1; j >= 0; j--) {
if (str[j] >= '7')
str[j] = '4', c = 1;
else if (str[j] >= '4')
str[j] = '7', c = 0;
else
str[j] = '4', c = 0;
if (c == 0) break;
}
if (c == 1) {
l++;
if (l & 1) l++;
int o = l / 2;
str = string(o, '4') + string(o, '7');
return;
}
} else if (str[i] > '4') {
str[i] = '7';
for (int j = i + 1; j < l; j++) str[j] = '4';
} else {
str[i] = '4';
for (int j = i + 1; j < l; j++) str[j] = '4';
}
}
int a4 = 0, a7 = 0;
int key = -1;
for (int i = 0; i < l; i++) {
if (str[i] == '4') {
if (a4 <= l / 2 && a7 + 1 <= l / 2) key = i;
}
if (str[i] == '4')
a4++;
else
a7++;
}
if (a4 == a7) return;
if (key == -1) {
int o = l / 2 + 1;
str = string(o, '4') + string(o, '7');
return;
}
a4 = a7 = 0;
for (int i = 0; i < key; i++) {
if (str[i] == '4')
a4++;
else
a7++;
}
str[key++] = '7';
a7++;
while (a4++ < l / 2) str[key++] = '4';
while (a7++ < l / 2) str[key++] = '7';
}
int main() {
string str;
cin >> str;
refrain(str);
cout << str << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int N = 100100;
char x[N];
int main() {
scanf("%s", x + 1);
x[0] = '0';
int k = strlen(x + 1);
if (k % 2 == 1) {
k = k / 2 + 1;
for (int i = 0; i < k; i++) printf("4");
for (int i = 0; i < k; i++) printf("7");
puts("");
return 0;
}
for (int i = k; i >= 1; i--) {
if (x[i] >= '8') {
x[i] = '0';
x[i - 1] += 1;
}
}
if (x[0] == '1') {
k += 1;
if (k % 2 == 1)
k = k / 2 + 1;
else
k = k / 2;
for (int i = 0; i < k; i++) printf("4");
for (int i = 0; i < k; i++) printf("7");
puts("");
return 0;
}
int h = k / 2;
int h4 = h, h7 = h;
bool ok = false;
for (int i = 1; i <= k; i++) {
if (!ok) {
if (x[i] < '4' && h4 > 0) {
x[i] = '4';
ok = true;
h4--;
} else if ((x[i] > '4' && x[i] < '7') || x[i] < '4') {
x[i] = '7';
ok = true;
h7--;
} else if (x[i] == '4' && h4 > 0)
h4--;
else {
x[i] = '7';
h7--;
}
} else {
if (h4 > 0) {
h4--;
x[i] = '4';
} else {
x[i] = '7';
h7--;
}
}
}
if (h4 == 0 && h7 == 0) {
for (int i = 1; i <= k; i++) printf("%c", x[i]);
puts("");
} else {
int now = 0, idx;
for (int i = 1; i <= k; i++) {
if (x[i] == '7') now += 1;
if (now == h) {
idx = i;
break;
}
}
bool has4 = false;
for (int i = idx; i >= 1; i--) {
if (x[i] == '4') {
has4 = true;
idx = i;
break;
}
}
if (has4) {
x[idx] = '7';
h4 = h7 = h;
for (int i = 1; i <= idx; i++) {
if (x[i] == '4') h4--;
if (x[i] == '7') h7--;
}
for (int i = idx + 1; i <= k; i++) {
if (h4 > 0) {
h4--;
x[i] = '4';
} else
x[i] = '7';
}
for (int i = 1; i <= k; i++) printf("%c", x[i]);
puts("");
} else {
k += 2;
k = k / 2;
for (int i = 0; i < k; i++) printf("4");
for (int i = 0; i < k; i++) printf("7");
puts("");
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
char s[100100];
char s1[100100];
int num[100100];
char res[100100];
void out(int n) {
for (int i = (0); i < (n); ++i)
if (i < n / 2)
printf("4");
else
printf("7");
printf("\n");
}
int n;
bool r(int p, int cnt1, int cnt2, bool f) {
if (p == n) {
if ((cnt1 == 0) && (cnt2 == 0)) return true;
return false;
}
if (f) {
if (cnt1 > 0) {
res[p] = '4';
bool ff = r(p + 1, cnt1 - 1, cnt2, f);
if (ff) return true;
} else {
res[p] = '7';
bool ff = r(p + 1, cnt1, cnt2 - 1, f);
if (ff) return true;
}
return false;
}
if (s[p] <= '4') {
if (cnt1 > 0) {
res[p] = '4';
bool f1 = false;
if (s[p] < '4') f1 = true;
bool ff = r(p + 1, cnt1 - 1, cnt2, f1);
if (ff) return true;
}
}
if (s[p] <= '7') {
if (cnt2 > 0) {
res[p] = '7';
bool f1 = false;
if (s[p] < '7') f1 = true;
bool ff = r(p + 1, cnt1, cnt2 - 1, f1);
if (ff) return true;
}
}
return false;
}
int main() {
scanf("%s", &s);
n = strlen(s);
if (n & 1) {
out(n + 1);
return 0;
}
for (int i = (0); i < (n); ++i)
if (i < n / 2)
s1[i] = '7';
else
s1[i] = '4';
bool f = true;
for (int i = (0); i < (n); ++i)
if (s1[i] > s[i])
break;
else if (s[i] > s1[i]) {
f = false;
break;
}
int cnt1 = 0, cnt2 = 0;
for (int i = (0); i < (n); ++i) {
if (s[i] == '4')
cnt1++;
else if (s[i] == '7')
cnt2++;
}
if (!f) {
out(n + 2);
return 0;
}
if ((cnt1 + cnt2 == n) && (cnt1 == cnt2)) {
for (int i = (0); i < (n); ++i) printf("%c", s[i]);
printf("\n");
return 0;
}
f = r(0, n / 2, n / 2, false);
for (int i = (0); i < (n); ++i) printf("%c", res[i]);
printf("\n");
return 0;
}
|
#include <bits/stdc++.h>
int n, m, i, j, a, b;
char s[100100], t[100100];
bool q;
void go(int m) {
for (i = 0; i < m; i++) putchar('4');
for (i = 0; i < m; i++) putchar('7');
}
int main() {
gets(s);
n = strlen(s);
if (n & 1) {
go((n + 1) / 2);
return 0;
}
a = b = n / 2;
for (i = 0; i < n; i++) {
if (s[i] != '4' && s[i] != '7') break;
if (s[i] == '4') {
t[i] = '4';
a--;
if (a == 0) break;
} else {
t[i] = '7';
b--;
if (b == 0) break;
}
}
if (s[i] != '4' && s[i] != '7') {
if (s[i] > '7') {
q = true;
} else if (s[i] > '4') {
t[i] = '7';
b--;
for (j = i + 1; j < n; j++)
if (a > 0) {
t[j] = '4';
a--;
} else {
t[j] = '7';
b--;
}
} else {
t[i] = '4';
a--;
for (j = i + 1; j < n; j++)
if (a > 0) {
t[j] = '4';
a--;
} else {
t[j] = '7';
b--;
}
}
} else
for (j = i + 1; j < n; j++)
if (a > 0) {
t[j] = '4';
a--;
} else {
t[j] = '7';
b--;
}
if (!q)
for (j = 0; j < n; j++)
if (s[j] != t[j]) {
if (s[j] > t[j]) break;
puts(t);
return 0;
}
if (q || j < n) {
for (j = i; j >= 0; j--)
if (t[j] == '4') break;
if (j < 0) {
go(n / 2 + 1);
return 0;
}
t[j] = '7';
a = b = n / 2;
for (i = 0; i <= j; i++)
if (t[i] == '4')
a--;
else
b--;
for (; i < n; i++)
if (a > 0) {
t[i] = '4';
a--;
} else {
t[i] = '7';
b--;
}
}
puts(t);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int mod = 1e8 + 7;
int main() {
char c[100005];
while (scanf("%s", c + 1) != EOF) {
char ans[100005];
memset(ans, 0, sizeof(ans));
for (int i = 1; c[i] != 0; i++) {
if (c[i] > '7') {
for (int j = i - 1; j >= 0; j--) {
if (ans[j] == '4') {
ans[j] = '7';
break;
} else {
ans[j] = '4';
}
}
for (int j = i; c[j] != 0; j++) ans[j] = '4';
break;
} else if (c[i] > '4') {
ans[i] = '7';
if (c[i] != '7') {
for (int j = i + 1; c[j] != 0; j++) ans[j] = '4';
break;
}
} else {
ans[i] = '4';
if (c[i] != '4') {
for (int j = i + 1; c[j] != 0; j++) ans[j] = '4';
break;
}
}
}
int f = 0, s = 0;
for (int i = 0; ans[i] != 0 || i == 0; i++) {
if (ans[i] == '4')
f++;
else if (ans[i] == '7')
s++;
}
if ((f + s) % 2 != 0) {
int num = (f + s) / 2 + 1;
for (int i = 0; i < num; i++) printf("4");
for (int i = 0; i < num; i++) printf("7");
continue;
} else if (f < s) {
int num = (f + s) / 2 + 1;
int ok = 0;
for (int i = strlen(ans + 1); i >= 0; i--) {
if (ans[i] == '7') {
f++;
s--;
} else if (ans[i] == '4' && f - s >= 2) {
ans[i] = '7';
f--;
s++;
for (int j = i + 1; ans[j] != 0; j++) ans[j] = '4';
for (int j = strlen(ans + 1); f != s; j--) {
ans[j] = '7';
f--;
s++;
}
ok = 1;
break;
}
}
if (!ok) {
for (int i = 0; i < num; i++) printf("4");
for (int i = 0; i < num; i++) printf("7");
continue;
}
}
{
for (int i = strlen(ans + 1); f > s; i--)
if (ans[i] == '4') {
ans[i] = '7';
f--;
s++;
}
if (ans[0])
printf("%s", ans);
else
printf("%s", ans + 1);
}
}
}
|
#include <bits/stdc++.h>
using namespace std;
long long gcd(long long x, long long y) { return !y ? x : gcd(y, x % y); }
int main() {
string str, ans;
int n, idx, a, b;
cin >> str, n = str.size();
if (n % 2 || str > (string(n >> 1, '7') + string(n >> 1, '4')))
cout << string(n / 2 + 1, '4') + string(n / 2 + 1, '7') << endl;
else {
if (n & 1) n++, str += '0';
ans = string(n >> 1, '4') + string(n >> 1, '7'), idx = a = b = n >> 1;
for (long long i = 0; i < int(n); i++)
if (str[i] == '4' || str[i] == '7')
ans[i] = str[i];
else if (str[i] < '4') {
ans[i] = '4', idx = i + 1;
for (long long j = 0; j < int(i + 1); j++) ans[j] == '4' ? a-- : b--;
while (a) a--, ans[idx++] = '4';
while (b) b--, ans[idx++] = '7';
break;
} else if (str[i] < '7') {
ans[i] = '7', idx = i + 1;
for (long long j = 0; j < int(i + 1); j++) ans[j] == '4' ? a-- : b--;
while (a) a--, ans[idx++] = '4';
while (b) b--, ans[idx++] = '7';
break;
} else {
for (long long j = i - 1; j > -1; j--)
if (ans[j] == '4') {
ans[j] = '7';
for (long long k = 0; k < int(j + 1); k++)
ans[k] == '4' ? a-- : b--;
for (long long k = j + 1; k < n; k++)
if (a)
ans[k] = '4', a--;
else
ans[k] = '7';
break;
}
break;
}
a = b = 0;
for (long long i = 0; i < int(n); i++) ans[i] == '4' ? a++ : b++;
if (a != b)
if (a < b) {
int tmp = n / 2 - a + 1, now = 0;
for (long long i = n - 1; i > -1; i--)
if (ans[i] == '7')
now++;
else if (now >= tmp) {
ans[i] = '7';
for (long long j = i + 1; j < n; j++)
if (ans[j] == '7' && tmp)
tmp--, ans[j] = '4';
else if (!tmp)
break;
break;
}
} else {
int tmp = n / 2 - b;
for (long long i = n - 1; i > -1; i--)
if (ans[i] == '4' && tmp)
tmp--, ans[i] = '7';
else if (!tmp)
break;
}
hell:
cout << ans << endl;
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
long long n;
cin >> n;
vector<long long> ans;
string str = "47";
ios::sync_with_stdio(0);
cin.tie(0);
while (str.size() <= 8) {
do {
ans.push_back(stoi(str));
} while (next_permutation(str.begin(), str.end()));
str += "47";
sort(str.begin(), str.end());
}
ans.push_back(4444477777);
for (int i = 0; i < ans.size(); ++i) {
if (ans[i] >= n) {
cout << ans[i];
break;
}
}
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
void pt(long long int n) {
long long int d = n / 2;
long long int t = 4;
for (int i = 1; i <= n; ++i) {
cout << t;
if (i == d) t = 7;
}
}
int main() {
string s;
cin >> s;
if (s.length() % 2 == 1) {
pt(s.length() + 1);
return 0;
}
long long int n = s.length();
long long int fo = 0, se = 0;
for (int i = 0; i < s.length(); ++i) {
if (s[i] != '4' && s[i] != '7') {
if (s[i] < '4') {
char b = '4';
for (int j = i, k = fo; j < s.length(); ++j, ++k) {
if (k == n / 2) b = '7';
s[j] = b;
}
cout << s;
return 0;
} else if (s[i] < '7') {
if (se == n / 2) {
long long int f = 0;
for (int j = i - 2; j >= 0; --j)
if (s[j] == '4' && s[j + 1] == '7') {
f = 1;
s[j] = '7';
long long int fo = 0;
long long int se = 0;
for (int k = 0; k <= j; ++k) {
if (s[k] == '4')
++fo;
else
++se;
}
char b = '4';
for (int k = j + 1, l = fo; k < s.length(); ++k, ++l) {
if (l == n / 2) b = '7';
s[k] = b;
}
cout << s;
return 0;
}
if (f == 0) {
pt(s.length() + 2);
return 0;
}
}
se++;
s[i] = '7';
char b = '4';
for (int j = i + 1, k = fo; j < s.length(); ++j, ++k) {
if (k == n / 2) b = '7';
s[j] = b;
}
cout << s;
return 0;
} else {
if (se == n / 2) {
long long int f = 0;
for (int j = i - 2; j >= 0; --j)
if (s[j] == '4' && s[j + 1] == '7') {
f = 1;
s[j] = '7';
long long int fo = 0;
long long int se = 0;
for (int k = 0; k <= j; ++k) {
if (s[k] == '4')
++fo;
else
++se;
}
char b = '4';
for (int k = j + 1, l = fo; k < s.length(); ++k, ++l) {
if (l == n / 2) b = '7';
s[k] = b;
}
cout << s;
return 0;
}
if (f == 0) {
pt(s.length() + 2);
return 0;
}
}
long long int f = 0;
for (int j = i - 1; j >= 0; --j)
if (s[j] == '4') {
f = 1;
s[j] = '7';
long long int fo = 0;
long long int se = 0;
for (int k = 0; k <= j; ++k) {
if (s[k] == '4')
++fo;
else
++se;
}
char b = '4';
for (int k = j + 1, l = fo; k < s.length(); ++k, ++l) {
if (l == n / 2) b = '7';
s[k] = b;
}
cout << s;
return 0;
}
if (f == 0) {
pt(s.length() + 2);
return 0;
}
}
} else if (s[i] == '4')
++fo;
else
++se;
if (fo == n / 2 + 1) {
for (int j = i; j < s.length(); ++j) s[j] = '7';
cout << s;
return 0;
} else if (se == n / 2 + 1) {
long long int f = 0;
for (int j = i - 2; j >= 0; --j)
if (s[j] == '4' && s[j + 1] == '7') {
f = 1;
s[j] = '7';
long long int fo = 0;
long long int se = 0;
for (int k = 0; k <= j; ++k) {
if (s[k] == '4')
++fo;
else
++se;
}
char b = '4';
for (int k = j + 1, l = fo; k < s.length(); ++k, ++l) {
if (l == n / 2) b = '7';
s[k] = b;
}
cout << s;
return 0;
}
if (f == 0) {
pt(s.length() + 2);
return 0;
}
}
}
cout << s;
}
|
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