poj 2907 dfs

#include<iostream>
#include<cstdio>
///題意:Karel在起始位置處,有n個位置有beepers,
///現在Karel要從起始位置出發将這n個beepers拿到,
///然後再回到起始位置,求這條路徑的最小值.直接DFS求解.
#include<cstring>
#include<cstdlib>
#include<algorithm>
using namespace std;
int t,n,m,vis[402],x[402],y[402],ans,st,ed,edx,edy;
void dfs(int step,int num,int x1,int y1)
{
    int i,j;
    if(num==m)
    {
        int len=abs(x1-st)+abs(y1-ed)+step;
        if(len<ans)ans=len;
        return;
    }
    if(step>ans)return;
    for(i=1;i<=m;i++)
    {
        if(!vis[i])
        {
            vis[i]=1;
            int len=abs(x[i]-x1)+abs(y[i]-y1);
            dfs(step+len,num+1,x[i],y[i]);
            vis[i]=0;
        }
    }
}
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        int i,j;
        scanf("%d%d",&edx,&edy);
        scanf("%d%d",&st,&ed);
        memset(vis,0,sizeof(vis));
        ans=400;
        scanf("%d",&m);
        for(i=1;i<=m;i++)
        {
            scanf("%d%d",&x[i],&y[i]);
        }
        dfs(0,0,st,ed);
        printf("The shortest path has length %d\n",ans);
    }
    return 0;
}
/*
1
10 10
1 1
4
2 3
5 5
9 4
6 5
*/