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42 lines
751 B
C++
42 lines
751 B
C++
#include <bits/stdc++.h>
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using std::cin;
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using std::cout;
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using std::endl;
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int n, m, fa[500005];
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long long ans;
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struct node {
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int u, v, w;
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bool operator<(const node x) const {
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return w < x.w;
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}
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} g[500005];
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int find(int x) {
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return fa[x] = fa[x] != x ? find(fa[x]) : fa[x];
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}
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int main() {
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cin >> n >> m;
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for (int i = 0; i < m; i++) {
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cin >> g[i].u >> g[i].v >> g[i].w;
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}
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std::sort(g, g + m);
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for (int i = 1; i <= n; i++) {
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fa[i] = i;
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}
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for (int i = 0; i < m; i++) {
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g[i].u = find(g[i].u);
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g[i].v = find(g[i].v);
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if (g[i].u != g[i].v) {
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fa[g[i].u] = g[i].v;
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ans += g[i].w;
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}
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}
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cout << ans << endl;
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return 0;
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}
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