Android 笔试---二分法查找

二分查找法

[cpp] view plaincopy
int binSearch(int key,int length, int array[])  
{  
        int mid=0;  
        int start = 0;  
        int end = length - 1;  
        while (start <= end) {  
              mid = (end - start) / 2 + start;  
              if (key == array[mid]) {  
                     return mid;  
              }  
              if (key < array[mid]) {  
                     end = mid - 1;  
               } else if (key > array[mid]) {  
                     start = mid + 1;  
               } else {  
                     return mid;  
               }  
        }  
        return -1;  
}