二分查找 模板（升序数组）

1 int binSearch(const int arr[],int low,int high,int key)
2 {
3    if(low>high)
4         return -1;
5    int mid=low+(high-low)/2;
6    if(arr[mid] == key)
7         return mid;
8    return (arr[mid] > key ? binSearch(arr,low,mid-1,key) : binSearch(arr,mid+1,high,key));
9 }