43 lines
856 B
C++
43 lines
856 B
C++
#include<cstdio>
|
|
#include<cmath>
|
|
using namespace std;
|
|
#define N 50005
|
|
int f[N], rank[N], n, m;
|
|
void init(){
|
|
for(int i=0; i<=n; ++i)
|
|
f[i]=i, rank[i]=0;
|
|
}
|
|
int find(int x){
|
|
if(x==f[x]) return f[x];
|
|
int t=f[x];
|
|
f[x] = find(f[x]);
|
|
rank[x] += rank[t];
|
|
return f[x];
|
|
}
|
|
bool Union(int x,int y, int m){
|
|
int a=find(x), b=find(y);
|
|
if(a==b){
|
|
if(rank[x]+m!=rank[y])
|
|
return false;
|
|
return true;
|
|
}
|
|
f[b] = a;
|
|
rank[b] = rank[x]+m-rank[y];
|
|
return true;
|
|
}
|
|
int main(){
|
|
int a,b,x;
|
|
while(~scanf("%d%d",&n,&m)){
|
|
init();
|
|
int cnt=0;
|
|
for(int i=0; i<m; ++i){
|
|
scanf("%d%d%d",&a,&b,&x);
|
|
if(!Union(a, b, x)){
|
|
++cnt;
|
|
}
|
|
}
|
|
printf("%d\n",cnt);
|
|
}
|
|
return 0;
|
|
}
|