treap

来源：互联网发布：淘宝上二手ipad良心店编辑：程序博客网时间：2024/05/17 07:15

写了treap..总算是过了。。

先写个递归版的非class版练练手，过几天写一个class当模板

treap=tree+heap

对于每一个，都给一个键值key,要求这个BST在保持BST性质的同时在key上也保持一个heap性质，这样就可以防止一大条链的情况

旋转和正常的差不多。。

在SPOJ3273上跑了4s+[SPOJ真TM慢。。]

#include<cstdio>#include<ctime>#include<cstring>#include<iostream>#include<algorithm>#include<cstdlib>using namespace std;struct node{node *lson,*rson;int value,key,size;node(int v) :value(v),key(rand()),size(1),lson(NULL),rson(NULL){};void maintain(){if (!this) return;size=1;if (lson!=NULL) size+=lson->getsize();if (rson!=NULL) size+=rson->getsize();}int getsize(){return this?size:0;}};inline void rotate_l(node* &root){node* tmp=root->rson;root->rson=tmp->lson;tmp->lson=root;tmp->maintain();root->maintain();root=tmp;}inline void rotate_r(node* &root){node* tmp=root->lson;root->lson=tmp->rson;tmp->rson=root;tmp->maintain();root->maintain();root=tmp;}inline void forever(node* &root,const int &value){if (root==NULL){root=new node(value);return;}if (value==root->value) return;if (value<root->value){forever(root->lson,value);if (root->lson->key>root->key)rotate_r(root);}else{forever(root->rson,value);if (root->rson->key>root->key)rotate_l(root);}root->maintain();}inline void forget(node* &root,const int &value){if (root==NULL) return;if (value==root->value){if (root->lson && root->rson){if (root->lson->key>root->rson->key){rotate_r(root);forget(root->rson,value);}else{rotate_l(root);forget(root->lson,value);}}else{node* tmp=root;root=root->rson?root->rson:root->lson;delete tmp;return;}}elseif (value<root->value)forget(root->lson,value);elseforget(root->rson,value);root->maintain();}inline node* kth(node* root,int k){if (root==NULL) return NULL;int tmp=root->lson->getsize();if (k-1==tmp) return root;elseif ((k-1)<tmp)return kth(root->lson,k);elsereturn kth(root->rson,k-tmp-1);}inline int rank(node* root,const int &value){if (root==NULL) return 0;int tmp=root->lson->getsize();if (value==root->value)return tmp+1;elseif (value<root->value)return rank(root->lson,value);else return rank(root->rson,value)+tmp+1;}node *root;int n,t;char a,str[20];inline void write(int k){if (k>root->getsize())printf("invalid\n");elseprintf("%d\n",kth(root,k)->value);}int main(){freopen("treap.in","r",stdin);freopen("treap.out","w",stdout);srand(unsigned(time));scanf("%d\n",&n);for (int i=1;i<=n;i++){        scanf("%s%d",str,&t);//        cout<<i<<"OK!\n";//cout<<i<<' '<<a<<endl;//cout<<"if "<<i<<" is a null"<<(root?1:0)<<endl;a=str[0];if (a=='I')forever(root,t);if (a=='D')forget(root,t);if (a=='K')write(t);if (a=='C')printf("%d\n",rank(root,t-1));//cout<<root->getsize()<<endl;}return 0;}

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