题解

#include<iostream>
using namespace std;
int main(){
    int n,k,ans=-1;
    cin>>n>>k;
    int a[n+10];
    for(int i=0;i<n;i++){
        cin>>a[i];
    }
    int l=0,r=n-1;
    while(l<=r){
        int mid=(l+r)>>1;
        if(a[mid]<=k){
            l=mid+1;
            ans=mid+1;
        }else{
            r=mid-1;
        }
    }
    if(ans==-1){
        cout<<-1;
    }else{
        cout<<a[ans-1];
    }
    return 0;
}