【HDOJ】1716 排列2

STL。

/* 1716 */
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;

#define MAXN 30
int b[MAXN];

int main() {
    int a[4];
    int t = 0, n;
    int i, j, k;
    
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
        freopen("data.out", "w", stdout);
    #endif
    
    while (1) {
        j = 0;
        for (i=0; i<4; ++i) {
            scanf("%d", &a[i]);
            j += a[i];
        }
        if (j == 0)
            break;
        if (t++)
            printf("
");
        sort(a, a+4);
        n = 0;
        do {
            if (a[0]) {
                b[n++] = 1000*a[0]+100*a[1]+10*a[2]+a[3];
            }
        } while (next_permutation(a, a+4));
        b[n] = 0;
        for (i=0; i<n; ++i) {
            j = b[i]/1000;
            k = b[i+1]/1000;
            if (j == k)
                printf("%d ", b[i]);
            else
                printf("%d
", b[i]);
        }
    }
    
    return 0;
}