NOJ---1567 --- Binary Search

My code has not been submitted on OJ because our OJ crashes again =-=

Touch me

= He just handed in, but it should be right, because the great God helped me solve the endless loop problem.

L = Mid + 1 and L = mid

In a strict sense, it is still different. When my condition is --- mid = (L + r)/2, then it is biased towards L and should adopt the first method.

If mid = (L + R + 1)/2, R should be written as mid-1

 

The second question is not difficult.

The basic framework of binary is similar to that of binarysearch.

This still depends on the specific question =-=

 1 #include <iostream> 2 using namespace std; 3  4 int n , m; 5 const int size = 500010; 6 int arr[size]; 7  8 bool bSearch( int x ) 9 {10     int cnt;11     cnt = 0;12     for( int i = 0 ; i<n ; i++ )13     {14         cnt += ( arr[i] + (x - 1) ) / x;15     }16     return cnt<=m;17 }18 19 int main()20 {21     int l , r;22     int mmax;23     while( ~scanf("%d %d",&n,&m) )24     {25         mmax = 0;26         if( n==-1 && m==-1 )27             break;28         for( int i = 0 ; i<n ; i++ )29         {30             scanf( "%d",&arr[i] );31             if( arr[i]>mmax )32             {33                 mmax = arr[i];34             }35         }36         l = 0;37         r = mmax;38         while( l<r )39         {40             int mid = l+(r-l)/2;41             if( bSearch(mid) )42             {43                 r = mid;44             }45             else46             {47                 l = mid+1;    48             }49         }50         cout<<l<<endl;51     }52     return 0;53 } 

View code

 

Today:

I don't know if we each have a destiny, or just floating around-like on a breeze