并查集——关押罪犯

关押罪犯

Time Limit:1000MS  Memory Limit:65536K

Description

Input

Output

Sample Input

4 6
1 4 2534
2 3 3512
1 2 28351
1 3 6618
2 4 1805
3 4 12884

Sample Output

3512

Hint

 

//具体详见以下题解
 1 #include<cstdio>
#include<algorithm> 
#define MAXN 100100
using namespace std;
struct node{
    int x,y,w;
}e[MAXN];
int father[MAXN<<1];
int n,m;
bool cmp(node a,node b){
    return a.w>b.w;
}
int find(int x){
    if(father[x]!=x)father[x]=find(father[x]);
    return father[x];
}
int main(){
    int i;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;++i){
        scanf("%d%d%d",&e[i].x,&e[i].y,&e[i].w);
    }
    for(i=1;i<=n<<1;++i){
        father[i]=i;
    }
    sort(e+1,e+m+1,cmp);
    for(i=1;i<=m;++i){
        int rx=find(e[i].x);
        int ry=find(e[i].y);
        if(rx==ry){
            printf("%d",e[i].w);
            return 0;
        }
        father[rx]=find(e[i].y+n);
        father[ry]=find(e[i].x+n);
    }printf("0");
return 0;}