NYOJ19擅长排列的小明

#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);
}
}