【演算法拾遺】二分尋找遞迴非遞迴實現

標籤：二分尋找

轉載請註明出處：http://blog.csdn.net/ns_code/article/details/33747953

    本篇博文沒太多要說的，二分尋找很簡單，也是常見常考的尋找演算法，以下是遞迴非遞迴的實現。

    非遞迴實現：

/*非遞迴實現,返回對應的序號*/int BinarySearch(int *arr,int len,int key){if(arr==NULL || len<1)return -1;int low = 0;int high = len-1;while(low <= high){int mid = (low+high)>>1;if(key == arr[mid])return mid;else if(key < arr[mid])high = mid-1;elselow = mid+1;}return -1;}

    遞迴實現：

/*遞迴實現,返回對應的序號*/int BSearch(int *arr,int low,int high,int key){if(arr==NULL || low>high)return -1;int mid = (low+high)>>1;if(arr[mid] == key)return mid;else if(arr[mid] > key)return BSearch(arr,low,mid-1,key);elsereturn BSearch(arr,mid+1,high,key);}/*將遞迴實現的方法封裝起來*/int BinSearch(int *arr,int len,int key){return BSearch(arr,0,len-1,key);}