【模拟赛】【最小生成树】2021.8.10.B

题目描述

最小生成树模板
即使不只派出一个通讯员，也可以全部点连向0号点处理

代码

#include
#include
#include
#include
#define ll long long 
using namespace std;

struct wh_
{
     
	ll w, h, k;
}wh[1000250];

ll t, n, k, tot, l, sum;
ll Fa[2005];

void hw(ll x, ll y, ll z)
{
     wh[++t] = (wh_) {
     x, y, z};}

bool nm(wh_ i, wh_ j)
{
     return i.k < j.k;}

ll find(ll k)
{
     
	if(k != Fa[k])return Fa[k] = find(Fa[k]);
	else return k;
}

ll read()
{
     
	ll x = 0, r = 1; char c = getchar();
	while(c < '0' || c > '9'){
     if(c == '-')r = -1;c = getchar();}
	while('0' <= c && c <= '9')x = x * 10 + c - 48, c = getchar();
	return x * r;
}


int main()
{
     
	n = read();
	for(ll i = 1; i <= n; ++i)
		for(ll j = 1; j <= n; ++j)
		{
     
			k = read();
			if(i > j)hw(i, j, k);
		}
	for(ll i = 1; i <= n; ++i)
	{
     
		k = read();
		hw(0, i, k), Fa[i] = i;
	}
	tot = 0, l = 0;
	sort(wh + 1, wh + t + 1, nm);
	while(tot < n && ++l)
	{
     
		ll x = wh[l].w, y = wh[l].h;
		ll xx = find(x);
		ll yy = find(y);
		if(xx == yy)continue;
		Fa[max(xx, yy)] = min(xx, yy);
		tot++, sum += wh[l].k;
	}
	printf("%lld", sum);
	return 0;
}