Ramana731/Permutations-of-string

#include <stdio.h> #include <stdlib.h> #include <string.h>

int next_permutation(int n, char **s) {

int k = -1;
for (int i = 0; i < n-1; i++) {
    if (strcmp(s[i], s[i+1]) < 0)
        k = i;
}
if (k == -1) return 0; 

int l = -1;
for (int i = k+1; i < n; i++) {
    if (strcmp(s[k], s[i]) < 0)
        l = i;
}

char *tmp = s[k];
s[k] = s[l];
s[l] = tmp;

int i = k+1, j = n-1;
while (i < j) {
    tmp = s[i];
    s[i++] = s[j];
    s[j--] = tmp;
}

return 1; 

}

int main() { char *s; int n; scanf("%d", &n); s = calloc(n, sizeof(char)); for (int i = 0; i < n; i++) { s[i] = calloc(11, sizeof(char)); scanf("%s", s[i]); } do { for (int i = 0; i < n; i++) printf("%s%c", s[i], i == n - 1 ? '\n' : ' '); } while (next_permutation(n, s)); for (int i = 0; i < n; i++) free(s[i]); free(s); return 0; }