Agri-Net 1558 Agri-Net

PS: 简单的最小生成树, 省赛热身。

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
using namespace std;
const int maxn = 110;
struct edges {
    int u, v, w;
};

int n;
vector<edges> G;
int f[maxn+5];

int getFather(int x) {
    if(x==f[x]) return x;
    else return f[x] = getFather(f[x]);
}

bool cmp(edges a, edges b) {
     return a.w < b.w;
}

int work() {
    sort(G.begin(), G.end(), cmp);
    for(int i = 1; i < maxn; i++) f[i] = i;
    int cnt = 0;
    int ans = 0;
    edges t;
    for(int i = 0; i < (int)G.size(); i++) {
        t = G[i];
        int t1 = getFather(t.u);
        int t2 = getFather(t.v);
        if(t1!=t2) {
            f[t1] = t2;
            ans += t.w;
            cnt++;
            if(cnt==n-1) break;
        }
    }
    return ans;
}


int main()
{
    int tmp;
    edges t;
    while(scanf("%d", &n)!=EOF) {
        G.clear();
        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= n; j++) {
                scanf("%d", &tmp);
                if(i!=j) {
                    t.u = i;
                    t.v = j;
                    t.w = tmp;
                    G.push_back(t);
                }
            }
        }
        int res = work();
        printf("%d\n", res);
    }
    return 0;
}