HDU - 3038 / 3048 （带权并查集） （待补）

 1 #include <cstdio>
 2 #include <iostream>
 3 #include <algorithm>
 4 using namespace std;
 5 
 6 const int N=200010;
 7 int Father[N],value[N];
 8 
 9 int find(int x){
10     if(x==Father[x]) return x;
11     int tmp=Father[x];
12     Father[x]=find(Father[x]);
13     value[x]+=value[tmp];
14     return Father[x];
15 }
16 
17 int Union(int x,int y,int len){
18     int fx=find(x),fy=find(y);
19     if(fx==fy){
20         if(value[x]+len!=value[y]) return 0;
21         return 1;
22     }    
23     Father[fy]=fx;
24     value[fy]=value[x]-value[y]+len;
25     return 1;
26 }
27 
28 int main(){
29     int n,m;
30     int a,b,c;
31     while(scanf("%d %d",&n,&m)!=EOF){
32         int ans=0;
33         for(int i=0;i<=n;i++) value[i]=0,Father[i]=i;
34         for(int i=1;i<=m;i++){
35             scanf("%d %d %d",&a,&b,&c);
36             if(!Union(a,b,c)) ans++;
37         }
38         printf("%d\n",ans);
39     }
40     return 0;
41 }