POJ 3723

思路： 最小生成樹算法統計絕對值最大權重和

#include <stdio.h>
#include <map>
#include <algorithm>

using namespace std;

int tree[20010];
int num_boy, num_girl, num_cost;

struct link
{
	int ID_boy;
	int ID_girl;
	int cost;
};

link l[50050];

bool cmp(const link &fomar, const link &later)
{
	return fomar.cost < later.cost;
}

void init()
{
	for (int i = 0; i < num_boy+num_girl; ++i)
	{
		tree[i] = i;
	}
}

int root(int i)
{
	if(i == tree[i])
		return i;
	return tree[i] = root(tree[i]);
}

int same(int a, int b)
{
	if(root(a) == root(b))
		return 1;
	return 0;
}

void connect(int a, int b)
{
	int root_a = root(a);
	int root_b = root(b);
	tree[root_a] = root_b;
}

int mintree()
{
	init();
	int diff = 0;
	sort(l, l+num_cost, cmp);
	for (int i = 0; i < num_cost; ++i)
	{
		int now_boy = l[i].ID_boy;
		int now_girl = l[i].ID_girl;
		int now_cost = l[i].cost;
		if(same(now_boy, now_girl))
			continue;
		diff += now_cost;
		connect(now_boy, now_girl);
	}
	return diff;
}

int main()
{
	int T;
	scanf("%d", &T);
	while(T--)
	{
		scanf("%d %d %d", &num_boy, &num_girl, &num_cost);
		int res = (num_boy+num_girl)*10000;

		for (int i = 0; i < num_cost; ++i)
		{
			int temp_boy, temp_girl, temp_cost;
			scanf("%d %d %d", &temp_boy, &temp_girl, &temp_cost);
			l[i].ID_boy = temp_boy;
			l[i].ID_girl = temp_girl+num_boy;
			l[i].cost = -temp_cost;
		}
		printf("%d\n", res + mintree());
	}
}