[HDU3038]How Many Answers Are Wrong（并查集）

传送门

和某题类似，只不过奇偶换成了和。

——代码

 #include <cstdio>
 #include <iostream>
 #define N 1000001

 int n, m, ans;
 int f[N], d[N];

 inline int read()
 {
     int x = , f = ;
     char ch = getchar();
     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -;
     for(; isdigit(ch); ch = getchar()) x = (x << ) + (x << ) + ch - '';
     return x * f;
 }

 inline int find(int x)
 {
     if(x ^ f[x])
     {
         int fx = f[x];
         f[x] = find(f[x]);
         d[x] += d[fx];
     }
     return f[x];
 }

 int main()
 {
     int i, x, y, z, fx, fy;
     while(~scanf("%d %d", &n, &m))
     {
         ans = ;
         for(i = ; i <= n; i++) f[i] = i, d[i] = ;
         for(i = ; i <= m; i++)
         {
             x = read() - ;
             y = read();
             z = read();
             fx = find(x);
             fy = find(y);
             if(fx == fy)
             {
                 if((d[x] - d[y]) ^ z) ans++;
             }
             else
             {
                 d[fx] = d[y] - d[x] + z;
                 f[fx] = fy;
             }
         }
         printf("%d\n", ans);
     }
     return ;
 }