include

include

include

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; 

}