学步园

坑爹的格式。。

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int a[4],hash1[4],vis[4],hash2[10000];
int flag,temp,cnt;
void Show(){
    int num = hash1[0] * 1000 + hash1[1] * 100 + hash1[2] * 10 + hash1[3];
    if(hash2[num]) return;
    else{
        hash2[num] = 1;
        if(temp != hash1[0]){
            cnt = 0;
            temp = hash1[0];
            flag++;
            if(flag) printf("\n");
        }

        if(cnt != 0) printf(" ");
        for(int i = 0;i < 4;i++){
            printf("%d",hash1[i]);
        }
        cnt++;
    }
    return ;
}
void Dfs(int x){
    if(x == 4){
        Show();
        return ;
    }
    for(int i = 0;i < 4;i++){
        if(x == 0 && a[i] == 0)continue;
        if(!vis[i]){
            hash1[x] = a[i];
            vis[i] = 1;
            Dfs(x + 1);
            vis[i] = 0;
        }
    }
}
int main(){
    int k = 0;
    while(~scanf("%d%d%d%d",&a[0],&a[1],&a[2],&a[3])){
        if(!a[0] && !a[1] && !a[2] && !a[3]) break;
        if(k)printf("\n");
        sort(a,a+4);
        memset(hash1,0,sizeof(hash1));
        memset(hash2,0,sizeof(hash2));
        memset(vis,0,sizeof(vis));
        temp = -1,flag = -1,cnt = 0;
        Dfs(0);
        printf("\n");
        k++;
    }
    return 0;
}