hdu3038 How Many Answers Are Wrong 种类并查集

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;

 int n, m;
 const int maxn = ;
 int fa[maxn];
 int sum[maxn];

 int Find(int x){
     if (x == fa[x])
         return x;
     else{
         int t = fa[x];
         fa[x] = Find(fa[x]);
         sum[x] += sum[t];
         return fa[x];
     }
 }

 bool Set_Union(int x, int y, int s){
     int fx = Find(x);
     int fy = Find(y);
     if (fx == fy && sum[x] != sum[y] + s)
         return false;
     else if(fx != fy){
         if (fx > fy){
             fa[fy] = fx;
             sum[fy] = sum[x] - s - sum[y];
         }
         else{
             fa[fx] = fy;
             sum[fx] = s + sum[y] - sum[x];
         }
     }
     return true;
 }

 void init(){
     memset(sum, , sizeof(sum));    //必须初始化为零
     for (int i = ; i <= n; i++){
         fa[i] = i;
     }
 }

 int main(){
     while (scanf("%d %d", &n, &m) != EOF){
         init();        //初始化
         int ans = ;
         while (m--){
             int a, b, s;
             scanf("%d%d%d", &a, &b, &s);
             a--;
             if (!Set_Union(a, b, s)){
                 ans++;
             }
         }
         printf("%d\n", ans);
     }
     //system("pause");
     return ;
 }