Ruby实现二分法查找

  

def binary_search
  a = [10,57,68,70,78,90,122]
  search = 78
  index = 0 , start_index = 0 , end_index = a.length
  while(true)
    index = start_index + ((end_index - start_index) / 2)
    start_index = index if a[index] < search
    end_index = index if a[index] > search
    break if a[index] == search
   end
   puts  "find by"+ index
end

def binary_search
  a = [10,57,68,70,78,90,122]
  search = 78
  index = 0 , start_index = 0 , end_index = a.length
  while(true)
    index = start_index + ((end_index - start_index) / 2)
    start_index = index if a[index] < search
    end_index = index if a[index] > search
    break if a[index] == search
   end
   puts  "find by"+ index
end

 

Java

 

 

public static void main(String[] args) {
            // sorted array
            int[] a = {10,57,68,70,78,90,122};
            //
            int search = 78;
            int index = 0;
            int start = 0;
            int end = a.length;
            while(true){
                //get index
                index = start+((end-start)/2);
                if(a[index]<search){
                    start = index;
                }else if(a[index]>search){
                    end = index;
                }else{
                    break;
                }
            }
            System.out.println("find by "+ index);
     }