bzoj3224: Tyvj 1728 普通平衡树

来源：互联网发布：如何屏蔽公司网络监控编辑：程序博客网时间：2024/04/30 03:10

链接：http://www.lydsy.com/JudgeOnline/problem.php?id=3224

题意：中文题。

分析：treap模板练习。其实知道了怎么旋转就知道了整个treap啦，实现的时候注意细节即可。

代码：

#include<map>#include<set>#include<cmath>#include<queue>#include<bitset>#include<math.h>#include<vector>#include<string>#include<stdio.h>#include<cstring>#include<iostream>#include<algorithm>#pragma comment(linker, "/STACK:102400000,102400000")using namespace std;const int N=15;const int M=1e5+7;const int HASHSIZE=3e5+9;const int mod=100000000;const int MOD1=1000000007;const int MOD2=1000000009;const double EPS=0.00000001;typedef long long ll;const ll MOD=1000000007;const int INF=~0u>>1;const ll MAX=1ll<<55;const double pi=acos(-1.0);typedef double db;typedef unsigned long long ull;struct Treap {    struct node {        node *son[2];        int key,siz,wei,cnt;        node(int _key,node *f) {            son[0]=son[1]=f;            key=_key;siz=cnt=1;wei=rand();        }        void pushup() {            siz=son[0]->siz+son[1]->siz+cnt;        }    }*null,*root;    Treap() {        null=new node(0,0);        null->siz=null->siz=0;        null->wei=INF;root=null;    }    void rot(node* &rt,bool d) {        node* c=rt->son[!d];rt->son[!d]=c->son[d];        c->son[d]=rt;rt->pushup();c->pushup();rt=c;    }    void insert(const int &key,node* &rt) {        if (rt==null) {            rt=new node(key,null);return ;        }        if (key==rt->key) {            rt->cnt++;rt->siz++;return ;        }        bool d=key>rt->key;        insert(key,rt->son[d]);        if (rt->wei>rt->son[d]->wei) rot(rt,!d);        rt->pushup();    }    void remove(const int &key,node* &rt) {        if (rt==null) return ;        bool d=key>rt->key;        if (key==rt->key) {            if (rt->cnt>1) {                rt->cnt--;rt->siz--;return ;            }            d=rt->son[0]->wei>rt->son[1]->wei;            if (rt->son[d]==null) {                delete rt;rt=null;return ;            }            rot(rt,!d);remove(key,rt->son[!d]);        } else remove(key,rt->son[d]);        rt->pushup();    }    node* select(int k,node* rt) {        int s=rt->son[0]->siz+rt->cnt;        if (k>=rt->son[0]->siz+1&&k<=s) return rt;        if (s>k) return select(k,rt->son[0]);        else return select(k-s,rt->son[1]);    }    int rank(const int &key,node* rt) {        if (rt==null) return 0;        int s=rt->son[0]->siz+rt->cnt;        if (key==rt->key) return rt->son[0]->siz+1;        if (key<rt->key) return rank(key,rt->son[0]);        else return s+rank(key,rt->son[1]);    }    int pre(const int &k) {        node* t=root;int ret=0;        while (t!=null)        if (t->key<k) ret=t->key,t=t->son[1];        else t=t->son[0];        return ret;    }    int sub(const int &k) {        node* t=root;int ret=0;        while (t!=null)        if (t->key>k) ret=t->key,t=t->son[0];        else t=t->son[1];        return ret;    }};int main(){    int i,a,b,n;    Treap tree;    scanf("%d", &n);    while (n--) {        scanf("%d%d", &a, &b);        if (a==1) tree.insert(b,tree.root);        if (a==2) tree.remove(b,tree.root);        if (a==3) printf("%d\n", tree.rank(b,tree.root));        if (a==4) printf("%d\n", tree.select(b,tree.root)->key);        if (a==5) printf("%d\n", tree.pre(b));        if (a==6) printf("%d\n", tree.sub(b));    }    return 0;}

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