二叉搜索树 并查集

struct node{
    int data;
    node* lch,*rch;
};
node* insert(node* p,int x){
    if(p==NULL){
        node* q = new node;
        q->data = x;
        q->lch = q->rch = NULL;
        return q;
    }else{
        if(x<p-data) p->lch = (p->lch,x);
        else p->rch = insert(p->rch,x);
        return p;
    }
}
bool find(node* p,int x){
    if(p==NULL) return false;
    if(x<p->data) return find(p->lch,x);
    else if(x==p->data) return true;
    else return find(p->rch,x);
}
node* remove(node* p,int x){
    //分三种情况考虑
    if(p==NULL) return NULL;
    else if(x<p->data) p->lch = remove(p->lch,x);
    else if(x>p->data) p->rch = remove(p->rch,x);
    else if(p->lch == NULL){
        node* q = p->rch;
        delete p;
        return q;
    }else if(p->lch->rch == NULL){
        node * q = p->lch;//直接将左孩子提上去，将新节点的右孩子就是原来删除节点的右孩子。
        q->rch = p->rch;
        delete p;
        return q;
    }else{
         node* q;
         for(q=p->lch;q->rch->rch!=NULL;q=q->rch);
         node* r = q->rch;
         q->rch =r->lch;
         r->lch = p->lch;
         r->rch = p->rch;
         delete p;
         return r;
    }
}

并查集

#include <iostream>

using namespace std;
const int MAX = 100;
int par[MAX],rank[MAX];

void init(int n){
    for(int i=0;i<n;i++){
        par[i] = i;//没有边
        rank[i] = 0;
    }
}
int find(int x){
    if(par[x]==x)
        return x;
    else
        return par[x] = find(par[x]);
}
void unite(int x,int y){
    x = find(x);
    y = find(y);
    if(x==y) return;
    if(rank[x]<rank[y]){
        par[x] = y;
    }else{
        par[y] = x;
        if(rank[x]==rank[y]){
            rank[x]++;
        }
    }
}
bool same(int x,int y){
    return find(x) == find(y);
}