POJ2395Out of Hay[Check set]

#include<iostream>#include<algorithm>#include<stdio.h>#include<string.h>using namespace std;#define fr(i,a,b) for(int i=(a),i_end=(b);i<=i_end;i++)#define frd(i,a,b) for(int i=(a),i_end=(b);i>=i_end;i--)#define ll long long#define pri(x) printf("%d",x)#define mes(x) memset(x,0,sizeof(x))#define prin(x) printf("%d\n",x)#define ln putchar('\n')int f[10010];int get(int x){    if(x!=f[x])        f[x]=get(f[x]);    return f[x];}struct node{    int x,y,z;}r[10010];int cmp(node a,node b){    return a.z<b.z;}int n,m,s,ans;int main(){    scanf("%d%d",&n,&m);    fr(i,1,m)        scanf("%d%d%d",&r[i].x,&r[i].y,&r[i].z);    sort(r+1,r+m+1,cmp);    s=0;    fr(i,1,n)        f[i]=i;    fr(i,1,m)        if(get(r[i].x)!=get(r[i].y)){            f[get(r[i].y)]=f[get(r[i].x)];            s++;            if(s==n-1){                ans=i;                break;            }        }    printf("%d",r[ans].z);    ln;    return 0;}