并查集 poj食物链

#include <iostream>#include <stdio.h>using namespace std;int par[50000],kin[50000];void init(int n){int i;for(i=0;i<n;i++){par[i] = i;kin[i] = 0;}}void uniun(int xroot,int yroot,int x,int y,int o){par[yroot] = xroot;kin[yroot] = (kin[x]-kin[y]-o+3)%3;}int find(int x){if(par[x] == x)return x;int xroot;xroot = find(par[x]);kin[x] = (kin[par[x]]+kin[x]+3)%3;par[x] = xroot;return xroot;}int main(){int n,k;int x,y,o;int count = 0;scanf("%d%d",&n,&k);init(n);while(k--){scanf("%d%d%d",&o,&x,&y);x--;y--;if(x>=n||y>=n){count++;continue;}int xroot = find(x);int yroot = find(y);if(xroot == yroot){int u = (kin[x] - kin[y]+3)%3;if(u==0 && o == 1){continue;}if(u == 1 && o == 2){continue;}count++;}else{uniun(xroot,yroot,x,y,o-1);}}printf("%d\n",count);return 0;}

一般父类便为更节点更新节点时 kin = 0