OJ-Problems-Source/HDOJ/3742_autoAC.cpp
2016-09-04 14:14:07 +08:00

41 lines
1.0 KiB
C++

#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 1000000 + 10;
struct Node{
int a, b, val;
}node[maxn];
int parent[maxn];
bool cmp(const Node &a, const Node &b){
return a.val < b.val ;
}
void Init(int num){
for(int i=0; i<num; i++)
parent[i] = i;
}
int main(){
int n, m;
while(cin >>n >>m, n||m){
int ans = 0, i;
for( i=0; i<m; i++){
cin >>node[i].a >>node[i].b >>node[i].val;
}
sort(node, node+m, cmp);
Init(n);
for( i=0; i<m; i++){
if( node[i].a == parent[node[i].a] || node[i].b == parent[node[i].b])
ans = ans > node[i].val ? ans : node[i].val;
parent[ node[i].a ] = -1;
parent[ node[i].b ] = -1;
}
for( i=0; i<n; i++)
if(parent[i] == i)
break;
if(i < n)
cout <<"IMPOSSIBLE" <<endl;
else
cout <<ans <<endl;
}
return 0;
}