整体二分--bzoj3110: [Zjoi2013]K大数查询

和整体二分的套路一样，但是单点修改改成了区间修改，用线段树维护就好啦

因为一开始看错题不带了改就把所有值取负改成求区间第k小了（逃

 

详解在https://blog.youkuaiyun.com/sizeof_you/article/details/81738217

 

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#define maxn 50005
#define ls cur<<1
#define rs cur<<1|1
#define LL long long
#define re register
using namespace std;
int n,m,now1,now2;
LL ans[maxn];

inline int rd(){
    int x=0,f=1;char c=' ';
    while(c<'0' || c>'9') {if(c=='-')f=-1;c=getchar();}
    while(c<='9' && c>='0') x=x*10+c-'0',c=getchar();
    return x*f;
}

struct Query{
    int a,b,typ,num; LL c,cnt;
}q[maxn],q1[maxn],q2[maxn];
inline bool cmp(Query x,Query y) {return x.num<y.num;}
struct TREE{
    int l,r; LL sum,lazy;
}node[maxn<<2];

inline void pushup(int cur){
    node[cur].l=node[ls].l, node[cur].r=node[rs].r;
    node[cur].sum=node[ls].sum+node[rs].sum;
}

inline void build(int cur,int L,int R){
    if(L==R){
        node[cur].l=node[cur].r=L; node[cur].sum=0; return;
    }
    int mid=(L+R)>>1;
    build(ls,L,mid); build(rs,mid+1,R);
    pushup(cur);
}

inline void pushdown(int cur){
    node[ls].sum+=node[cur].lazy*(node[ls].r-node[ls].l+1);
    node[rs].sum+=node[cur].lazy*(node[rs].r-node[rs].l+1);
    node[ls].lazy+=node[cur].lazy; node[rs].lazy+=node[cur].lazy;
    node[cur].lazy=0; 
}

inline void update(int cur,int L,int R,LL c){
    if(L<=node[cur].l && node[cur].r<=R){
        node[cur].sum+=c*(node[cur].r-node[cur].l+1);
        node[cur].lazy+=c; return;
    }
    pushdown(cur);
    int mid=(node[cur].l+node[cur].r)>>1;
    if(L<=mid) update(ls,L,R,c);
    if(mid<R) update(rs,L,R,c);
    pushup(cur);
}

inline LL query(int cur,int L,int R){
    if(L<=node[cur].l && node[cur].r<=R)
        return node[cur].sum;
    pushdown(cur);
    int mid=(node[cur].l+node[cur].r)>>1;
    LL tot=0;
    if(L<=mid) tot+=query(ls,L,R);
    if(mid<R) tot+=query(rs,L,R);
    return tot;
}

inline void calc(LL vl,LL vr,int l,int r){
    for(re int i=l;i<=r;i++)
        if(q[i].typ==2)
            q[i].cnt=query(1,q[i].a,q[i].b);
        else if(q[i].typ==1 && q[i].c<=vr)
            update(1,q[i].a,q[i].b,1);
    for(re int i=l;i<=r;i++)
        if(q[i].typ==1 && q[i].c<=vr) update(1,q[i].a,q[i].b,-1);
    now1=now2=0;
    for(re int i=l;i<=r;i++)
        if(q[i].typ==2)
            if(q[i].c<=q[i].cnt) q1[++now1]=q[i];
            else q[i].c-=q[i].cnt, q2[++now2]=q[i];
        else
            if(q[i].c<=vr) q1[++now1]=q[i];
            else q2[++now2]=q[i];
    int now=l;
    for(re int i=1;i<=now1;i++) q[now++]=q1[i];
    for(re int i=1;i<=now2;i++) q[now++]=q2[i];
}

inline void solve(int l,int r,LL vl,LL vr){
    if(vl==vr){
        for(re int i=l;i<=r;i++)
            if(q[i].typ==2) ans[q[i].num]=vl;
        return;
    }
    LL mid=(vl+vr)>>1;
    calc(vl,mid,l,r);
    int tmp=now1;
    if(tmp) solve(l,l+tmp-1,vl,mid);
    if(l+tmp<=r) solve(l+tmp,r,mid+1,vr);
    return;
}

int main(){
    n=rd(); m=rd(); build(1,1,n);
    for(re int i=1;i<=m;i++){
        q[i].typ=rd(); q[i].num=i;
        if(q[i].typ==1){
            q[i].a=rd(),q[i].b=rd(); scanf("%lld",&q[i].c);
            q[i].c=-q[i].c;
        }
        else{
            q[i].a=rd(),q[i].b=rd(); scanf("%lld",&q[i].c);
        }
    }
    solve(1,m,-n,n);
    sort(q+1,q+m+1,cmp);
    for(re int i=1;i<=m;i++)
        if(q[i].typ==2) printf("%lld\n",-ans[i]);
    return 0; 
}