luogu 2617

https://www.luogu.org/problemnew/show/2617

整体二分比树套树高级多了

#include<cstdio>
#include<algorithm>
#define FOR(i,s,t) for(register int i=s;i<=t;++i)
const int N=1000011;
struct question{
	int t,p,x,y,k,cnt,cur;
}q[N],s[N];
int ans[N];
int tr[N],a[N],tmp[N];
int n,m,tot,cnt,x,y,inf;
char c;
inline int max(int a,int b){return a>b?a:b;}
inline void add(int p,int v){for(;p<=n;p+=p&-p)tr[p]+=v;}
inline int query(int p){int ret=0;for(;p;p-=p&-p)ret+=tr[p];return ret;}
inline void solve(int h,int t,int l,int r){
	if(h>t)return;
	if(l==r){
		FOR(i,h,t)ans[q[i].cnt]=l;
		return;
	}
	int mid=(l+r)>>1;
	FOR(i,h,t){
		if(q[i].t!=3&&q[i].x<=mid)q[i].t==1?add(q[i].p,1):add(q[i].p,-1);
		if(q[i].t==3)tmp[i]=query(q[i].y)-query(q[i].x-1);
	}
	FOR(i,h,t)if(q[i].t!=3&&q[i].x<=mid)q[i].t==1?add(q[i].p,-1):add(q[i].p,1);
	int tail=h,d;
	FOR(i,h,t){
		if(q[i].t==3&&q[i].cur+tmp[i]>=q[i].k)s[tail++]=q[i];
		if(q[i].t!=3&&q[i].x<=mid)s[tail++]=q[i];	
	}
	d=tail-1;
	FOR(i,h,t){
		if(q[i].t==3&&q[i].cur+tmp[i]<q[i].k)q[i].cur+=tmp[i],s[tail++]=q[i];
		if(q[i].t!=3&&q[i].x>mid)s[tail++]=q[i];
	}
	FOR(i,h,t)q[i]=s[i];
	solve(h,d,l,mid);
	solve(d+1,t,mid+1,r);
}
int main(){
	scanf("%d%d",&n,&m);
	FOR(i,1,n){
		scanf("%d",a+i);
		inf=max(inf,a[i]);
		q[++tot].t=1;q[tot].p=i;q[tot].x=a[i];q[tot].cnt=0;
	}
	FOR(i,1,m){
		scanf("\n%c",&c);
		if(c=='Q'){
			q[++tot].t=3;
			scanf("%d%d%d",&q[tot].x,&q[tot].y,&q[tot].k);
			q[tot].cnt=++cnt;
		}
		else{
			scanf("%d%d",&x,&y);
			q[++tot].t=2;q[tot].p=x;q[tot].x=a[x];q[tot].cnt=0;
			a[x]=y;inf=max(inf,y);
			q[++tot].t=1;q[tot].p=x;q[tot].x=a[x];q[tot].cnt=0;
		}
	}
	solve(1,tot,0,inf);
	FOR(i,1,cnt)printf("%d\n",ans[i]);
	return 0;
}