NYOJ19擅长排列的小明

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=19

一个深搜就搞定了。。

代码：

#include <cstdio>#include <cstring>int n,m;int a[15];int v[15];void dfs(int step){     if(step == m + 1)     {         for(int i = 1;i <= m;++i)            printf("%d",a[i]);         printf("\n");         return ;     }     for(int i = 1;i <= n;++i)     {         if(!v[i])         {             a[step] = i;             v[i] = 1;             dfs(step + 1 );             v[i] = 0;         }     }}int main(){     int _;     scanf("%d",&_);     while(_--)     {         memset(v,0,sizeof v);         scanf("%d%d",&n,&m);         dfs(1);     }}