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48 lines
1.0 KiB
48 lines
1.0 KiB
#include <bits/stdc++.h>
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using namespace std;
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const int N = 2010, M = 10010;
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int n, m, p[N];
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struct Edge {
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int a, b, c;
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bool operator<(const Edge &t) const {
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return c < t.c;
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}
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} edge[M];
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int el;
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int find(int x) {
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if (p[x] != x) p[x] = find(p[x]);
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return p[x];
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}
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int res;
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int main() {
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cin >> n >> m;
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// 初始化并查集
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for (int i = 1; i <= n; i++) p[i] = i;
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for (int i = 0; i < m; i++) {
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int a, b, c, t;
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cin >> t >> a >> b >> c;
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if (t == 1) // 必选的加入到同一个并查集
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p[find(a)] = find(b), res += c;
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else
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// 记录可选边有哪些
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edge[el++] = {a, b, c};
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}
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// 对可选边进行由小到大排序
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sort(edge, edge + el);
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// 枚举每条可选边
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for (int i = 0; i < el; i++) {
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int a = find(edge[i].a), b = find(edge[i].b), c = edge[i].c;
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if (a != b) p[a] = b, res += c;
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}
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// 输出最短长度
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cout << res << endl;
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return 0;
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} |