最长上升子序列II(c++实现)

#include<iostream>
using namespace std;
const int N=1e6+10;
int n,q[N],a[N];

int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d",&a[i]);
    int len=0;

    for(int i=1;i<=n;i++){
        int l=0,r=len;
        while(l<r){
            int mid = l+r+1>>1;
            if(q[mid]<a[i]) l=mid;
            else r=mid-1;
        }
        len = max(len,r+1);
        q[r+1] = a[i];
    }
    printf("%d",len);
}