BZOJ 3943 Usaco2015 Feb SuperBull Prim

题目大意

异或Prim。

思路

没开long long WA了一次你敢信？

CODE

#define _CRT_SECURE_NO_WARNINGS#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#define MAX 2010#define INF 0x3f3f3f3fusing namespace std;int points;int src[MAX];int f[MAX];bool v[MAX];long long Prim(){    long long re = 0;    for(int i = 1; i <= points; ++i) {        int max_length = 0, p = 1;        for(int j = 1; j <= points; ++j)            if(!v[j] && f[j] > max_length)                max_length = f[j], p = j;        v[p] = true;        re += max_length;        for(int j = 1; j <= points; ++j)            if(!v[j])                f[j] = max(f[j], src[p]^src[j]);    }    return re;}int main(){    cin >> points;    for(int i = 1; i <= points; ++i)        scanf("%d", &src[i]);    cout << Prim() << endl;    return 0;}