UVA - 471 Magic Numbers set ＋ vector

[code]#include<cstdio>
#include<cstring>
#include<vector>
#include<set>
using namespace std;

vector<long long> sum;
int vis[11];

void dfs(long long s) {
    sum.push_back(s);
    for(int i = 0; i < 10; i++)
        if(!vis[i]) {
            vis[i] = 1;
            dfs(s * 10 + i);
            vis[i] = 0;
        }
}

void init() {

    for(int i = 0; i < 11; i++)
        vis[i] = 0;
    for(int i = 0; i < 10; i++) {
        vis[i] = 1;
        dfs(i);
        vis[i] = 0;
    }
}

bool check(long long s) {
    int cnt[11], t;
    memset(cnt,0,sizeof(cnt));
    while(s) {
        t = s % 10;
        if(cnt[t])
            return false;
        cnt[t] = 1;
        s /= 10;
    }
    return true;
}

int main() {
    init();
    long long num;
    int test;
    scanf("%d", &test);
    for(int j = 0; j < test; j++){
        if(j)
            printf("\n");
        scanf("%lld", &num);
        set<long long> s;
        for(int i = 0; i < sum.size(); i++)
            if(sum[i] % num == 0 && sum[i] / num != 0 && check(sum[i] / num))
                s.insert(sum[i]);
        for(set<long long>::iterator i = s.begin(); i != s.end(); i++)
            printf("%lld / %lld = %lld\n", *i, (*i) / num, num);
    }
    return 0;
}