二分

#include<bits/stdc++.h>
using namespace std;


bool judge(int x)
{
}

int main()
{

    int l,r;
    //000000000111111111
    while(l < r)
    {
        int mid = l+r>>1;
        if(judge(mid))r = mid;
        else l = mid+1;
    }
    //111111111000000000
    while(l < r)
    {
        int mid = l+r+1>>1;
        if(judge(mid))l = mid;
        r = mid-1;
    }

   return 0;
}