问题 H: 局域网

#include<bits/stdc++.h>
#define inf 0x3f3f3f3f//洛谷 P2820 局域网（最小生成树）
#define ll long long
using namespace std;
const int  maxn = 1e5 + 10;
struct newt
{
    int from, to, cost;
}e[maxn];
int fa[110], n, m;
int fi(int x)
{
    if (x == fa[x])return x;
    return fa[x] = fi(fa[x]);
}
bool cmp(newt a, newt b)
{
    return a.cost < b.cost;
}
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= n; i++)fa[i] = i;
    int ans = 0;
    for (int i = 1; i <= m; i++)
        scanf("%d%d%d", &e[i].from, &e[i].to, &e[i].cost), ans += e[i].cost;
    sort(e + 1, e + m + 1, cmp);
    for (int i = 1; i <= m; i++)
    {
        int f1 = fi(e[i].from), f2 = fi(e[i].to);
        if (f1 != f2)
        {
            ans -= e[i].cost;
            fa[f1] = f2;
        }
    }
    printf("%d\n", ans);
    return 0;
}