最长不下降子序列【模板】

#include<bits/stdc++.h>
#define int long long
using namespace std;
int len,n,a[100009],g[100009];
signed main(){
	scanf("%ld",&n);
	for(int i=1;i<=n;i++) cin>>a[i];
	len=1;
	for(int i=2;i<=n;++i){
		if(g[len]<=a[i]){
			g[++len]=a[i];
		}else{
			for(int j=1;j<=len;j++){
				if(g[j]>a[i]){
					g[j]=a[i];
					break;
				}
			}
		}
	}
	cout<<len-1;
	return 0;
}