UESTC 1653 最小生成树？

题目链接：http://acm.uestc.edu.cn/#/problem/show/1653
题意：中文题面
解法：

#include <bits/stdc++.h>using namespace std;struct node{    int x,y;} p[1010];int n, dp[1010][1010], s[1010][1010];bool cmp(node a, node b){    if(a.x==b.x) return a.y>b.y;    return a.x<b.x;}int main(){    while(~scanf("%d", &n))    {        for(int i=1; i<=n; i++) scanf("%d %d", &p[i].x,&p[i].y);        sort(p+1,p+n+1,cmp);        memset(dp, 0x3f, sizeof(dp));        for(int i=1; i<=n; i++) s[i][i]=i,dp[i][i]=0;        for(int len = 2; len <= n; len++)        {            for(int l = 1; l+len-1<=n; l++)            {                int r = l+len-1;                for(int j=s[l][r-1]; j<=s[l+1][r]; j++)                {                    if(j!=r)                    {                        if(dp[l][j]+dp[j+1][r]+p[j+1].x-p[l].x+p[j].y-p[r].y<dp[l][r])                        {                            dp[l][r]=dp[l][j]+dp[j+1][r]+p[j+1].x-p[l].x+p[j].y-p[r].y;                            s[l][r]=j;                        }                    }                }            }        }        printf("%d\n", dp[1][n]);    }    return 0;}