最小生成树,稀疏图用kruskal,O(ElogE)
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
using namespace std;
#define maxr 50005
#define maxn 20005
struct Edge
{
int u, v, w;
} edge[maxr];
int father[maxn];
int n, m, r;
int ans;
bool operator < (const Edge &a, const Edge &b)
{
return a.w > b.w;
}
int getanc(int a)
{
if (father[a] == a)
return a;
return father[a] = getanc(father[a]);
}
void merge(int a, int b)
{
father[getanc(a)] = getanc(b);
}
void input()
{
scanf("%d%d%d", &n, &m, &r);
for (int i = 0; i < r; i++)
{
scanf("%d%d%d", &edge[i].u, &edge[i].v, &edge[i].w);
edge[i].v += n;
}
}
void work()
{
ans = 0;
for (int i = 0; i < n + m; i++)
father[i] = i;
for (int i = 0; i < r; i++)
{
if (getanc(edge[i].u) == getanc(edge[i].v))
continue;
merge(edge[i].u, edge[i].v);
ans += edge[i].w;
}
printf("%d\n", (n + m) * 10000 - ans);
}
int main()
{
//freopen("t.txt", "r", stdin);
int t;
scanf("%d", &t);
while (t--)
{
input();
sort(edge, edge + r);
work();
}
return 0;
}