bzoj 3196 && luogu 3380 JoyOI 1730 二逼平衡树 (线段树套Treap）

#include<bits/stdc++.h>
using namespace std;
#define ls t[x].ch[0]
#define rs t[x].ch[1]
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define mid int m = (l + r) >> 1
const int M = 1e5+10;
const int inf = 2147483647;
int idx,n;
struct node{
    int ch[2],cnt,siz,val,rd;
}t[M*50];
int root[M<<2],a[M];
void up(int x){
    t[x].siz = t[ls].siz + t[rs].siz+t[x].cnt;
}

void rotate(int &x,int d){
    int son = t[x].ch[d];
    t[x].ch[d] = t[son].ch[d^1];
    t[son].ch[d^1] = x; up(x); up(x=son);
}

void ins(int &x,int val){
    if(!x){
        x = ++idx;
        t[x].cnt = t[x].siz = 1;
        t[x].val = val,t[x].rd = rand();
        return ;
    }
    t[x].siz ++;
    if(t[x].val == val){
        t[x].cnt++; return ;
    }
    int d = t[x].val < val; ins(t[x].ch[d],val);
    if(t[x].rd > t[t[x].ch[d]].rd) rotate(x,d);
}

void del(int &x,int val){
    if(!x) return ;
    if(t[x].val == val){
        if(t[x].cnt > 1){
            t[x].cnt--,t[x].siz--;return ;
        }
        bool d = t[ls].rd > t[rs].rd;
        if(ls == 0||rs == 0) x = ls+rs;
        else rotate(x,d),del(x,val);
    }
    else t[x].siz--,del(t[x].ch[t[x].val<val],val);
    up(x);
}
int rk(int x,int val){
    if(!x) return 0;
    if(t[x].val == val) return t[ls].siz;
    if(t[x].val > val) return rk(ls,val);
    return rk(rs,val)+t[ls].siz + t[x].cnt;
}

int pre(int x,int val){
    if(!x) return -inf;
    if(t[x].val >= val) return pre(ls,val);
    return max(pre(rs,val),t[x].val);
}

int nex(int x,int val){
    if(!x) return inf;
    if(t[x].val <= val) return nex(rs,val);
    return min(nex(ls,val),t[x].val);
}

void print(int x){
    if(!x) return ;
    print(ls);
    printf("%d ",t[x].val);
    print(rs);
}

void update(int p,int l,int r,int rt){
    ins(root[rt],a[p]);
    if(l == r) return ;
    mid;
    if(p <= m) update(p,lson);
    else update(p,rson);
}

int get_rank(int L,int R,int c,int l,int r,int rt){
    if(L <= l&&R >= r){
        return rk(root[rt],c);
    }
    int ret = 0;
    mid;
    if(L <= m) ret += get_rank(L,R,c,lson);
    if(R > m) ret += get_rank(L,R,c,rson);
    return ret;
}

int get_val(int x,int y,int k){
    int l = 0,r = inf,ret ;
    while(l < r){
        mid;
        int ans = get_rank(x,y,m,1,n,1)+1;
        if(ans <= k) {
            ret = m;l = m+1;
        }
        else r = m;
    }
    return ret;
}

void change(int p,int c,int l,int r,int rt){
    del(root[rt],a[p]);
    ins(root[rt],c);
    if(l == r) return ;
    mid;
    if(p <= m) change(p,c,lson);
    else change(p,c,rson);
}

int get_pre(int L,int R,int c,int l,int r,int rt){
    if(L <= l&&R >= r){
        return pre(root[rt],c);
    }
    mid;
    int ret = -inf;
    if(L <= m) ret = max(ret,get_pre(L,R,c,lson));
    if(R > m) ret = max(ret,get_pre(L,R,c,rson));
    return ret;
}

int get_nex(int L,int R,int c,int l,int r,int rt){
    if(L <= l&&R >= r){
        return nex(root[rt],c);
    }
    mid;
    int ret = inf;
    if(L <= m) ret = min(ret,get_nex(L,R,c,lson));
    if(R > m) ret = min(ret,get_nex(L,R,c,rson));
    return ret;
}

void  ct(int l,int r,int rt){
    cout<<"L R: "<<l<<" "<<r<<endl;
    print(root[rt]); cout<<endl;
    if( l == r) return ;
    mid;
    ct(lson); ct(rson);
}

int main()
{
   // freopen("D:\\1.txt","r",stdin);
    //freopen("D:\\2.txt","w",stdout);
    int m,op,x,y,z;
    scanf("%d%d",&n,&m);
    for(int i = 1;i <= n;i ++){
        scanf("%d",&a[i]);
        update(i,1,n,1);
    }
     //ct(1,n,1);
    while(m--){
        scanf("%d",&op);
        scanf("%d%d",&x,&y);
        if(op!=3) scanf("%d",&z);
        if(op == 1)
            printf("%d\n",get_rank(x,y,z,1,n,1)+1);
        else if(op == 2)
            printf("%d\n",get_val(x,y,z));
        else if(op == 3)
            change(x,y,1,n,1),a[x]=y;
        else if(op == 4)
            printf("%d\n",get_pre(x,y,z,1,n,1));
        else if(op==5)
            printf("%d\n",get_nex(x,y,z,1,n,1));
    }
    return 0;
}