二分模板

 1 bool check(){
 2     if(/*满足二分条件*/)
 3         return true;
 4     return false;
 5 }
 6 
 7 int erfen(int size){
 8     int left=0,right=size;
 9     int mid;
10     while(left<right)
11     {
12         mid=(left+right)>>1;
13         if(check())
14             left=mid+1;
15         else
16             right=mid;
17     }
18     return left;
19 }