折半查找递归和非递归实现

 1 //data增序排列 
 3 //非递归折半查找
 4 int binarySearch(int * data, int keyValue, int len){
 5     int low=0,high=len-1,mid=0;
 6     while (low<=high)
 7     {
 8         mid=(low+high)/2;
 9         if(data[mid]==keyValue) return mid;
10         else if(data[mid]>keyValue)
11             high=mid-1;
12         else 
13             low=mid+1;
14     }
15     return -1;
16 }
17 
18 //递归折半查找
19 int* binarySearchRecursion(int * data, int keyValue, int len){
20     int low=0,high=len-1,mid=0;
21     if(low<=high){
22         mid=(low+high)/2;
23         if(data[mid]==keyValue) return data+mid;
24         else if (data[mid]>keyValue) return binarySearchRecursion(data,keyValue,mid);
25         else return binarySearchRecursion(data+mid+1,keyValue,high-mid);
26     }
27     return 0;
28 }