题目：53. 寻宝（第七期模拟笔试） (kamacoder.com)

最小生成树-prim算法

#include<bits/stdc++.h>using namespace std;int main(){int n, m;cin >> n >> m;vector<vector<int>> grid(n + 1, vector<int>(n + 1, 10001));while(m--) {int x, y;cin >> x >> y;cin >> grid[x][y];grid[y][x] = grid[x][y];}vector<int> minDist(n + 1, 10001);vector<bool> isTree(n + 1, false);int cur = 1;for(int i = 0;i < n;i++) {int min = 10001;for(int j = 1;j <= n;j++) {if(!isTree[j] && minDist[j] < min) {min = minDist[j];cur = j;}}isTree[cur] = true;for(int j = 1;j <= n;j++) {if(!isTree[j] && grid[cur][j] < minDist[j]) {minDist[j] = grid[cur][j];}}}int result = 0;for(int i = 2;i <= n;i++) {result += minDist[i];}cout << result << endl;return 0;
}

最小生成树-Kruskal 算法

#include<bits/stdc++.h>using namespace std;int n = 10001;
vector<int> father(10001, 0);
struct edge{int l, r, val;
};void init() {for(int i = 1;i <= n;i++) {father[i] = i;}
}int find(int x) {return x == father[x] ? x : father[x] = find(father[x]);
}void join (int u, int v) {u = find(u);v = find(v);if(u == v) return;father[v] = u;
}int main(){int m;cin >> n >> m;vector<edge> edges;while(m--) {int l, r, val;cin >> l >> r >> val;edges.push_back({l, r, val});}sort(edges.begin(), edges.end(), [](const edge& a, const edge& b){return a.val < b.val;});init();int result = 0;for(int i = 0;i < edges.size();i++) {if(find(edges[i].l) == find(edges[i].r)) continue;else {result += edges[i].val;join(edges[i].l, edges[i].r);}}cout << result << endl;}