UVA 729 - The Hamming Distance Problem

        下一个排列！next_permutation

#include<cstdio>#include<string>#include<algorithm>using namespace std;int main(){    int cas,n,h,a[19];    scanf("%d",&cas);    while(cas--)    {        scanf("%d %d",&n,&h);         for(int i=0;i<n-h;i++)         {             a[i]=0;             printf("%d",a[i]);         }         for(int i=n-h;i<n;i++)         {             a[i]=1;            printf("%d",a[i]);         }         putchar('\n');         while(next_permutation(a,a+n))         {             for(int i=0;i<n;i++)             printf("%d",a[i]);             putchar('\n');         }         if(cas)         putchar('\n');    }    return 0;}