Zoj 1542 [Kruskal algorithm]

The sample of zoj is incorrect. The problem is to find the Minimum Spanning Tree and the longest path.

#include <vector>#include <list>#include <map>#include <set>#include <string.h>#include <deque>#include <stack>#include <bitset>#include <algorithm>#include <functional>#include <numeric>#include <utility>#include <sstream>#include <iostream>#include <iomanip>#include <cstdio>#include <cmath>#include <cstdlib>#include <ctime>using namespace std;#define LL long long#define pi acos(-1)#define N 15010#define INF 999999999#define eps 1e-8//****************************************//zoj 1542 Network//Copyright@leolin. All rights reserved.//****************************************struct node{    int x,y,len;}e[N],hub[N];int fa[1100];int n,m;bool cmp(node a,node b){    return a.len<b.len;}int find(int x){    while(x!=fa[x])        x=fa[x];    return x;}void krasual(){    int i,j,k;    for(i=0;i<=n;i++)        fa[i]=i;    sort(e+1,e+m+1,cmp);    int max=0;    int cnt=0;    for(i=1;i<=m;i++)    {        int a=find(e[i].x);        int b=find(e[i].y);        if(a!=b)        {            fa[a]=b;            if(max<e[i].len)max=e[i].len;            hub[cnt++]=e[i];        }    }    printf("%d\n%d\n",max,cnt);    for(i=0;i<cnt;i++)    printf("%d %d\n",hub[i].x,hub[i].y);}int main(){//freopen("a.txt","r",stdin);    while(scanf("%d%d",&n,&m)!=EOF)    {        for(int i=1;i<=m;i++)            scanf("%d%d%d",&e[i].x,&e[i].y,&e[i].len);            krasual();    }    return 0;}