点一多，二维矩阵就存不下了
#include <cstdio> #include <iostream> #include <cstring> #include <algorithm> #include <queue> #define int long long using namespace std; const int N = 5000, INF = 0x3f3f3f3f; int n, m; int g[N][N]; int dist[N]; bool st[N]; int prim() { memset(dist, 0x3f, sizeof(dist)); int res = 0; for (int i = 0; i < n; i++) { int t = -1; for (int j = 1; j <= n; j++) if (!st[j] && (t == -1 || dist[t] > dist[j])) t = j; if (i) res += dist[t]; st[t] = true; for (int j = 1; j <= n; j++) dist[j] = min(dist[j], g[t][j]); } return res; } signed main() { std::ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n >> m; memset(g, 0x3f, sizeof(g)); while (m--) { int a, b, c; cin >> a >> b >> c; g[a][b] = g[b][a] = min(g[a][b], c); } int t = prim(); cout << t; return 0; }