题意

在一个点打井cost[i]，连接两个点dis[i][j]，求使所有点间接或直接与水井连通的最小花费

题解

对于在一个点打井，视为与0节点连一条边，然后krusual即可

调试记录

无

#include <cstdio>
#include <algorithm>
#define maxn 305

using namespace std;

struct node{
	int u, v, l;
}e[maxn * maxn << 2];
int tot = 0;
void addedge(int u, int v, int l){e[++tot] = (node){u, v, l};}
bool cmp(const node &a, const node &b){return a.l < b.l;}

int n, f[maxn];
int getf(int x){return (f[x] == x) ? x : f[x] = getf(f[x]);}
int Krusual(){
	sort(e + 1, e + tot + 1, cmp);
	for (int i = 1; i <= n; i++) f[i] = i;
	
	int res = 0;
	for (int i = 1; i <= tot; i++){
		if (getf(e[i].u) != getf(e[i].v)){
			f[getf(e[i].u)] = getf(e[i].v);
			res += e[i].l;
		}
	}
	return res;
}

int main(){
	scanf("%d", &n);
	
	for (int x, i = 1; i <= n; i++){
		scanf("%d", &x);
		addedge(0, i, x);
	}
	
	for (int x, i = 1; i <= n; i++)
		for (int j = 1; j <= n; j++){
			scanf("%d", &x);
			addedge(i, j, x);
		}
	
	printf("%d\n", Krusual());
	
	return 0;
}