BZOJ1503 NOI2004 郁闷的出纳员 平衡树

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <iostream>
#include <algorithm>
using namespace std;
#define Pushup(x) tree[x].cnt=tree[tree[x].child[0]].cnt+tree[tree[x].child[1]].cnt+1

const int MAXN=200000+2;
struct NODE{
    int value,cnt,child[2];
}tree[MAXN];
int N,Min,cnt,root,add;
char Order[2];

void Rotate(int &x,bool type){
    int y=tree[x].child[!type];
    tree[x].child[!type]=tree[y].child[type],tree[y].child[type]=x;
    tree[y].cnt=tree[x].cnt,Pushup(x);
    x=y;
}

void Maintain(int &x,bool type){
    if(tree[tree[tree[x].child[type]].child[type]].cnt>tree[tree[x].child[!type]].cnt) Rotate(x,!type);
    else if(tree[tree[tree[x].child[type]].child[!type]].cnt>tree[tree[x].child[!type]].cnt) Rotate(tree[x].child[type],type),Rotate(x,!type);
    else return;

    Maintain(tree[x].child[0],false),Maintain(tree[x].child[1],true);
    Maintain(x,true),Maintain(x,false);
}

void Insert(int &x,int value){
    if(x){
        tree[x].cnt++;
        if(value<tree[x].value) Insert(tree[x].child[0],value);
        else Insert(tree[x].child[1],value);
        Maintain(x,value>=tree[x].value);

    }
    else{
        x=++cnt;
        tree[x].child[0]=tree[x].child[1]=0;
        tree[x].cnt=1,tree[x].value=value;
    }
}

void Delete(int &x,int v,int minv){
    if(!x) return;

    if(tree[x].value+v<minv) Delete(x=tree[x].child[1],v,minv);
    else{
        Delete(tree[x].child[0],v,minv);
        Pushup(x);
    }
}

int Select(int &x,int k){
    int c=tree[tree[x].child[1]].cnt+1;

    if(c==k) return tree[x].value;
    else if(c<k) return Select(tree[x].child[0],k-c);
    else return Select(tree[x].child[1],k);
}

int main(){
    cin >> N >> Min;
    for(int k,t;N--;){
        scanf("%s %d",Order,&k);

        if(Order[0]==‘I‘ && k>=Min) Insert(root,k-add);
        if(Order[0]==‘A‘) add+=k;
        if(Order[0]==‘S‘) add-=k,Delete(root,add,Min);
        if(Order[0]==‘F‘) cout << (k>tree[root].cnt?-1:Select(root,k)+add) << endl;
    }
    cout << cnt-tree[root].cnt << endl;

    return 0;
}