CCF 201412-4 最优灌溉_Kruskal

CCF 201412-4 最优灌溉 传送门

以前的CCF第四题居然这么水, 出了一道裸的最小生成树. 写了6分钟就100分了. 光看题目, 最优灌溉, 还以为是网络流问题.

辣鸡代码, 不值一看

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

struct Edge {
    int from, to, cost;
    Edge () {}
    Edge (int f, int t, int c) : from(f), to(t), cost(c) {}
};

const int maxn = 1005;
int n, m, ans = 0, cnt = 0;
vector<Edge> edge;
int father[maxn];

bool cmp(Edge x, Edge y)
{
    return x.cost < y.cost;
}

int find(int x)
{
    return x == father[x] ? x:father[x] = find(father[x]);
}

int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; ++i)
        father[i] = i;
    for (int i = 0, u, v, c; i < m; ++i) {
        cin >> u >> v >> c;
        edge.push_back(Edge(u, v, c));
    }
    sort(edge.begin(), edge.end(), cmp);
    for (int i = 0; i < edge.size(); ++i) {
        int x = find(edge[i].from), y = find(edge[i].to);
        int cost = edge[i].cost;
        if (x != y) {
            ans += cost;
            cnt++;
            father[x] = y;
        }
        if (cnt == n - 1) {
            cout << ans;
            return 0;
        }
    }
}