ACM模板——并查集

#define _for(i,a,b) for(int i = (a);i < (b);i ++)
const int maxn = 50003;
int par[maxn]; //父亲 
int high[maxn]; //树的高度

void init(int n)
{
    _for(i,0,n)
    {
        par[i] = i;
        high[i] = 0;
    }
} 

int find(int x)
{
    return par[x] == x ? x : par[x] = find(par[x]);
}

void unite(int x,int y)
{
    x = find(x);y = find(y);
    if(x==y) return ;
    
    if(high[x]<high[y])
        par[x] = y;
    else
    {
        par[y] = x;
        if(high[x]==high[y])
            high[x] ++;
    }
}

bool same(int x,int y)
{
    return find(x) == find(y); 
}

路径压缩普通并查集