hihocoder 1329 splay 伸展树

来源：互联网发布：简阳市环保局何知云编辑：程序博客网时间：2024/05/22 05:45
自己写的伸展树用指针实现
删除那块还不是很理解
三个操作使树更加平衡的原理还有有待加深理解
有待加强
#include <bits/stdc++.h>#define N 101000#define FREI freopen("in.txt","r",stdin)#define FREO freopen("out.txt","w",stdout)#define Mem(a,b) memset(a,b,sizeof(a))#define lson root<<1#define rson root<<1|1#define Mid int mid=(l+r)>>1#define inf 0x3f3f3f3fusing namespace std;int res;struct node {    int num,weight;    node *left;    node *right;    node *father;};node *root,*ansp;node* Insert(node *&p,node *father,int val) {    if(p==0) {        p=(node*)malloc(sizeof(node));        p->num=val;        p->left=0;        p->right=0;        p->father=father;        return p;    }    if(val<p->num)        return Insert(p->left,p,val);    if(val>p->num)        return Insert(p->right,p,val);    return 0;}void left_rotate(node *x) {    node *p=x->father;    if(p==0)        return;    x->father=p->father;    if(x->father==0) root=x;    if(p->father!=0){        if(p->father->left==p)            p->father->left=x;        else            p->father->right=x;    }    p->right=x->left;    if(x->left!=0) x->left->father=p;    x->left=p;    p->father=x;}void right_rotate(node *x) {    node *p=x->father;    if(p==0)        return;    x->father=p->father;    if(x->father==0) root=x;    if(p->father!=0){        if(p->father->left==p)            p->father->left=x;        else            p->father->right=x;    }    p->left=x->right;    if(x->right!=0) x->right->father=p;    x->right=p;    p->father=x;}void splay(node *x,node *y){    while(x->father!=y){        node *p=x->father;        if(p->father==y){            if(p->left==x)                right_rotate(x);            else                left_rotate(x);        }        else{            node *g=p->father;            if(g->left==p){                if(p->left==x){                    right_rotate(p);                    right_rotate(x);                }                else{                    left_rotate(x);                    right_rotate(x);                }            }            else{                if(p->right==x){                    left_rotate(p);                    left_rotate(x);                }                else{                    right_rotate(x);                    left_rotate(x);                }            }        }    }}void Find(node *p,int val) {    if(p==0)        return;    if(p->num<=val) {        if(res<p->num){            res=p->num;            ansp=p;        }    }    if(val<p->num)        Find(p->left,val);    if(val>p->num)        Find(p->right,val);}node* Findpre(node *key){    node *p=key->left;    while(p->right)        p=p->right;    return p;}node* Findnext(node *key){    node *p=key->right;    while(p->left)        p=p->left;    return p;}node* Findkey(node *p,int val){    res=-inf;    Find(p,val);    splay(ansp,0);    return ansp;}void Insertkey(node *p,int val){    node *tmp=Insert(p,0,val);    if(tmp!=0) splay(tmp,0);}void Delete(node *a,node *b){    node *pre=Findpre(a);    node *next=Findnext(b);    splay(pre,0);    splay(next,pre);    next->left=0;}int main() {    //FREI;    //FREO;    int n;    scanf("%d",&n);    root=0;    Insert(root,0,inf);    Insert(root,0,-inf);    for(int i=1; i<=n; i++) {        char x;        scanf("\n%c",&x);        int val;        if(x=='I'){            scanf("%d",&val);            Insertkey(root,val);        }        if(x=='Q'){            scanf("%d",&val);            Findkey(root,val);            printf("%d\n",res);        }        if(x=='D'){            int l,r;            scanf("%d%d",&l,&r);            Insertkey(root,l);            Insertkey(root,r);            node *a=Findkey(root,l);            node *b=Findkey(root,r);            Delete(a,b);        }    }}
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