UVALIVE 3939 Plucking fruits

并查集解决。代码跑的有够慢。应该可以通过边权排序优化。

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <stack>
#include <queue>
#include <cctype>
#include <cstdio>
#include <string>
#include <vector>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define PI 3.1415926535897932626
using namespace std;
int gcd(int a, int b) {return a % b == 0 ? b : gcd(b, a % b);}
#define MAXN 1010
int p[MAXN];
int Find(int x) {return x == p[x] ? x : p[x] = Find(p[x]);}
int N,M,R;
struct node
{
        int u,v,w;
        friend bool operator < (const node &a,const node &b)
        {
                return a.w < b.w;
        }
}src[MAXN * MAXN];
bool judge(int s,int t)
{
        int x =Find(s);
        int y = Find(t);
        if (x == y) return true;
        return false;
}
bool query(int s,int t,int least)
{
        for (int i = 0 ; i < M ; i++)
        {
                if (src[i].w < least) continue;
                int x = Find(src[i].u), y = Find(src[i].v);
                if (x != y) p[x] = y;
                if (judge(s,t))
                {
                        return true;
                }
        }
        return false;
}
int main()
{
     int kase = 1;
     while (cin >> N >> M >> R)
     {
             cout << "Case " << kase++  << ':' << endl;
             for (int i = 0 ; i < M ;i++)
                cin >> src[i].u >> src[i].v >> src[i].w;
             for (int i = 0 ; i < R; i++)
             {
                     int u ,v,w;
                     for (int i = 0 ;i <= N ; i++) p[i] = i;
                     cin >> u >> v  >> w;
                     if (query(u,v,w)) puts("yes");
                     else puts("no");
             }
     }
     return 0;
}