cspsT1求算时间复杂度

#include<bits/stdc++.h>
using namespace std;
int read(){
	int w=1,x=0;
	char ch=0;
	while(ch<'0'||ch>'9'){
		if(ch=='-') w=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=x*10+(ch-'0');
		ch=getchar();
	}
	return w*x;
}
const int N=1e6+10;
int n,a[N];
int vis[N],att[N];

int search(int x){
	int l=0,r=n,mid;
	while(l<r-1){
		mid=(l+r)/2;
		if(!att[mid]&&!vis[mid]){
			if(a[mid]<=x) l=mid+1;
			else r=mid;
		}else{
			l++;
		}
	}
	return r;
	
	
}
int cnt=0;
int main(){
	n=read();
	for(int i=0;i<n;i++){
		a[i]=read();
	}
	sort(a,a+n);
	for(int i=0;i<n;i++){
		int v=search(a[i]);
		if(v==n){
			continue;
		}else{
			vis[i]=1;
			att[v]=1;
			cnt++;
		}
	}
	
	cout<<n-cnt;
}