最小生成树的模板题

不多说，可以看我之前写的最小生成树的博客

#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 10;
int pre[maxn];
struct node
{
    int u, v, e;
    bool operator<(const node x)
    {
        return e < x.e;
    }
} w[maxn];
int find(int x)
{
    return pre[x] == x ? x : pre[x] = find(pre[x]);
}
void join(int x, int y)
{
    pre[find(x)] = find(y);
}
int main()
{
    int n, m, ans = 0, sum;
    scanf("%d%d%d", &sum, &n, &m);
    for (int i = 1; i <= m; ++i)
        pre[i] = i;
    for (int i = 1; i <= n; ++i)
        scanf("%d%d%d", &w[i].u, &w[i].v, &w[i].e);
    sort(w + 1, w + n + 1);
    for (int i = 1; i <= n; ++i)
    {
        if (find(w[i].u) != find(w[i].v))
        {
            join(w[i].u, w[i].v);
            ans += w[i].e;
        }
    }
    if (ans <= sum)
        printf("Yes\n");
    else
        printf("No\n");
}