Niuke - Practice 101 - reasoning clown

Reasoning clown

Title Description

Main idea ：

This problem is mainly solved by an attempt .
Try from high to low .
If the high position can not be 1 Just be satisfied < Words , Then don't be high 1;
If the high position is not 1 Will appear > Words , Then the high position must be 1;
If appear = In the case of , Need to look back , If you can't, then 1.

#include<iostream>
#include<algorithm>
using namespace std;
const int N=1e5+10;
int n;
int a[N];
int main()
{
    
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>a[i];
    int ans=0;
    for(int i=30;i>=0;i--)
    {
    
        int now=ans;
        bool flag;
        for(int j=i-1;j>=0;j--)
        {
    
            now|=1<<j;
            flag=1;
            for(int k=1;k<n;k++) {
       if((a[k]&now)>(a[k+1]&now))
                {
    
                    flag=0;
                    break;
                }
            }
            if(!flag) now^=1<<j;
        }
        flag=1;
        for(int k=1;k<n;k++)
        {
    
            if((a[k]&now)>=(a[k+1]&now))
            {
    
                flag=0;
                break;
            }
        }
        if(!flag) ans|=1<<i;
    }
    cout<<ans<<endl;
    return 0;
}