Conscription

Conscription

Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 131072/65536K (Java/Other)

Total Submission(s) : 13   Accepted Submission(s) : 6

Problem Description

Windy has a country, and he wants to build an army to protect his country. He has picked up N girls and M boys and wants to collect them to be his soldiers. To collect a soldier without any privilege, he must pay 10000 RMB. There are some relationships between girls and boys and Windy can use these relationships to reduce his cost. If girl x and boy y have a relationship d and one of them has been collected, Windy can collect the other one with 10000-d RMB. Now given all the relationships between girls and boys, your assignment is to find the least amount of money Windy has to pay. Notice that only one relationship can be used when collecting one soldier.

 

Input

The first line of input is the number of test case.
The first line of each test case contains three integers, N, M and R.
Then R lines followed, each contains three integers x_i, y_i and d_i.
There is a blank line before each test case.

1 ≤ N, M ≤ 10000
0 ≤ R ≤ 50,000
0 ≤ x_i < N
0 ≤ y_i < M
0 < d_i < 10000

 

Output

For each test case output the answer in a single line.

 

Sample Input

2 5 5 8 4 3 6831 1 3 4583 0 0 6592 0 1 3063 3 3 4975 1 3 2049 4 2 2104 2 2 781 5 5 10 2 4 9820 3 2 6236 3 1 8864 2 4 8326 2 0 5156 2 0 1463 4 1 2439 0 4 4373 3 4 8889 2 4 3133

 

Sample Output

71071 54223

题解：

征兵：有n个女生，m个男生，其中每个人需要花费10000元。不过男生和女生之间有相互作用，可以降低费用。比如编号为1的女生和编号为1的男生之间有关系d，那么女生已经征兵结束后，男生只需10000-d即可入伍

kruskal算法，让男生直接+maxn就好；

代码：

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
const int MAXN=10010;
struct Node{
    int s,e,c;
};
int cmp(Node a,Node b){
    return a.c>b.c;
}
Node dt[MAXN*5];
int pre[MAXN*2];
int ans;
int find(int x){
    return pre[x]= x==pre[x]?x:find(pre[x]);
}
void initial(){
    memset(pre,-1,sizeof(pre));
    ans=0;
}
void merge(Node a){
        int f1,f2;
    if(pre[a.s]==-1)pre[a.s]=a.s;
    if(pre[a.e]==-1)pre[a.e]=a.e;
    f1=find(a.s);f2=find(a.e);
    if(f1!=f2){
        pre[f1]=f2;
        ans+=a.c;
    }
}
int main(){int N,M,R,T;
scanf("%d",&T);
    while(T--){
        scanf("%d%d%d",&N,&M,&R);
        initial();
        for(int i=0;i<R;i++){
            scanf("%d%d%d",&dt[i].s,&dt[i].e,&dt[i].c);
            dt[i].e+=MAXN;
        }
        sort(dt,dt+R,cmp);
        for(int i=0;i<R;i++){
            merge(dt[i]);
        }
        printf("%d\n",10000*(M+N)-ans);
    }
    return 0;
}