bzoj4552排序

Posted 2020-10-01 zcysky

二分一个值，然后线段树上模拟。

#include<bits/stdc++.h>
#define lson (o<<1)
#define rson (o<<1|1)
const int N=1e5+10;
using namespace std;
int n,m,a[N],x,q;
struct Opt{int opt,l,r,id;}b[N];
struct Segment_Tree{
    int sumv[N<<2],setv[N<<2];
    inline void pushup(int o){sumv[o]=sumv[lson]+sumv[rson];}
    inline void pushdown(int o,int l,int r){
        if(setv[o]==-1)return;
        int tag=setv[o],mid=(l+r)>>1;
        setv[lson]=tag;sumv[lson]=tag*(mid-l+1);
        setv[rson]=tag;sumv[rson]=tag*(r-mid);
        setv[o]=-1;
    }
    inline void build(int o,int l,int r){
        sumv[o]=0;setv[o]=-1;
        if(l==r){sumv[o]=a[l]>x;return;}
        int mid=(l+r)>>1;
        build(lson,l,mid);build(rson,mid+1,r);
        pushup(o);
    }
    int querysum(int o,int l,int r,int ql,int qr){
        if(ql<=l&&r<=qr)return sumv[o];
        int mid=(l+r)>>1,ans=0;
        pushdown(o,l,r);
        if(ql<=mid)ans+=querysum(lson,l,mid,ql,qr);
        if(qr>mid)ans+=querysum(rson,mid+1,r,ql,qr);
        return ans;
    } 
    void iset(int o,int l,int r,int ql,int qr,int v){
        if(ql<=l&&r<=qr){setv[o]=v;sumv[o]=v*(r-l+1);return;}
        int mid=(l+r)>>1;
        pushdown(o,l,r);
        if(ql<=mid)iset(lson,l,mid,ql,qr,v);
        if(qr>mid)iset(rson,mid+1,r,ql,qr,v);
        pushup(o);
    }
}T;
inline bool check(int vv){
    x=vv;
    T.build(1,1,n);
    for(int i=1;i<=m;i++){
        int opt=b[i].opt,l=b[i].l,r=b[i].r;
        int tmp=T.querysum(1,1,n,l,r);
        if(opt==0){
            T.iset(1,1,n,l,r-tmp,0);
            T.iset(1,1,n,r-tmp+1,r,1);
        } 
        else{
            T.iset(1,1,n,l,l+tmp-1,1);
            T.iset(1,1,n,l+tmp,r,0);
        }
    }
    return !T.querysum(1,1,n,q,q);
}
inline int read(){
    int f=1,x=0;char ch;
    do{ch=getchar();if(ch==‘-‘)f=-1;}while(ch<‘0‘||ch>‘9‘);
    do{x=x*10+ch-‘0‘;ch=getchar();}while(ch>=‘0‘&&ch<=‘9‘);
    return f*x;
}
int main(){
    n=read();m=read();for(int i=1;i<=n;i++)a[i]=read();
    for(int i=1;i<=m;i++){b[i].opt=read();b[i].l=read();b[i].r=read();}
    q=read();int l=1,r=n;
    while(l<r){
        int mid=(l+r)>>1;
        if(check(mid))r=mid;
        else l=mid+1;
    }
    printf("%d\n",r);
}