代码:
#include <iostream>using namespace std;const int N = 50010;int n, m;
int p[N], d[N];int find(int x)
{if(p[x] != x){int t = find(p[x]);d[x] += d[p[x]];p[x] = t;}return p[x];
}int main()
{scanf("%d%d", &n, &m);for(int i = 1; i <= n; i++) p[i] = i;int res = 0;while(m--){int t, x, y;scanf("%d%d%d", &t, &x, &y);if(x > n || y > n) res++;else{int px = find(x), py = find(y);if(t == 1){if(px == py && (d[x] - d[y]) % 3) res ++;else if(px != py){p[px] = py;d[px] = d[y] - d[x];}}else{if(px == py && (d[x] - d[y] - 1) % 3) res++;else if(px != py){p[px] = py;d[px] = d[y] + 1 - d[x];}}}}printf("%d", res);return 0;
}