50015. Words

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

char s[100];
int s_size;
int rule[26][26];
int cnt[26] = {0};

static inline void ipt(){
    scanf("%s", s);
    s_size = strlen(s);
    for(int i = 0; i < s_size; i++){
        cnt[s[i] - 'a']++;
    }

    int n; scanf("%d", &n);
    for(int i = 0; i < 26; i++){
        for(int j = 0; j < 26; j++){
            rule[i][j] = 0;
        }
    }
    for(int i = 0; i < n; i++){
        char temp[3]; scanf("%s", temp);
        rule[temp[0] - 'a'][temp[1] - 'a'] = 1;
    }
}

void get_comb(int cnt[26], char* target, int n){
    if(n == s_size){
        target[s_size] = '\0';
        printf("%s\n", target);
        return;
    }

    for(int i = 0; i < 26; i++){
        if(cnt[i] == 0) continue;
        if(n != 0 && rule[ target[n - 1] - 'a' ][i] == 1) continue;

        cnt[i]--; target[n] = (char)(i + 'a');
        get_comb(cnt, target, n + 1);
        target[n] = '\0'; cnt[i]++;
    }
}

int main() {
    ipt();

    char target[100] = {'\0'};
    get_comb(cnt, target, 0);
}