【luoguP2994】[USACO10OCT]吃晚饭的时候Dinner Time

题目链接

按顺序对于每个座位找一个最近的同时编号最小的牛就行了

#include<iostream>
#include<cstring>
#include<cstdio>
#define int long long
using namespace std;

const int MAXN=1010;
const int INF=1e18;

int n,m;

struct Data{
	int x,y;
} c[MAXN],s[MAXN];

bool ok[MAXN],used[MAXN];

inline int dis(int i,int j){
	return (c[i].x-s[j].x)*(c[i].x-s[j].x)+(c[i].y-s[j].y)*(c[i].y-s[j].y);
}

signed main()
{
//	freopen("a.in","r",stdin);
//	freopen("a.out","w",stdout);
	scanf("%lld%lld",&n,&m);
	for(int i=1;i<=n;++i)
		scanf("%lld%lld",&c[i].x,&c[i].y);
	for(int i=1;i<=m;++i)
		scanf("%lld%lld",&s[i].x,&s[i].y);
	for(int i=1;i<=m;++i){
		int k=-1,minn=INF;
		for(int j=1;j<=n;++j)
			if(!used[j]&&dis(j,i)<minn)
				k=j,minn=dis(j,i);
		used[k]=1;
	}
	bool flag=1;
	for(int i=1;i<=n;++i)
		if(!used[i]){
			printf("%lld
",i);
			flag=0;
		}
	if(flag) puts("0");
	return 0;
}