最小生成树

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
struct DSU {
    vector<int> parent;
    vector<int> sz;
    DSU(int n = 0) { init(n); }
    void init(int n) {
        parent.resize(n + 1);
        sz.resize(n + 1);
        for (int i = 0; i <= n; ++i) {
            parent[i] = i;
            sz[i] = 1;
        }
    }
    int find(int x) {
        if (parent[x] == x) return x;
        parent[x] = find(parent[x]);
        return parent[x];
    }
    bool unite(int a, int b) {
        a = find(a);
        b = find(b);
        if (a == b) return false;
        if (sz[a] < sz[b]) {
            int tmp = a; a = b; b = tmp;
        }
        parent[b] = a;
        sz[a] += sz[b];
        return true;
    }
};
struct Edge {
    int u;
    int v;
    int w;
};
bool cmpedg(const Edge& a, const Edge& b) {
    return a.w < b.w;
}
int main() {
    int n, m;
    cin>>n>>m;
    vector<Edge> edg;
    edg.reserve(m);
    for (int i = 0; i < m; ++i) {
        int x, y, z;
        cin >> x >> y >> z;
        edg.push_back({x, y, z});
    }
    sort(edg.begin(), edg.end(), cmpedg);
    DSU dsu(n);
    long long total = 0;
    int used = 0;
    for (size_t i = 0; i < edg.size(); ++i) {
        if (dsu.unite(edg[i].u, edg[i].v)) {
            total += edg[i].w;
            ++used;
            if (used == n - 1) break;
        }
    }
    int comps = 0;
    for(int i=1;i<=n;i++)
        if(dsu.find(i)==i) ++comps;
    if(comps==1) cout << total << '\n';
    else cout << "orz\n";
    return 0;
}