//在递增数组中，非递归算法下的二分查找，若找到目标数字，返回所在数组的下标位置；否则返回-1
int binarySearchByIteration(int arr[], int len, int findData)
{
if (arr == nullptr || len <= 0)
return -1;
int start = 0, end = len - 1, middle = 0;
while (end >= start)
{
middle = start + (end - start) / 2;
if (arr[middle] == findData)
return middle;
else if (arr[middle] < findData)
{
start = middle + 1;
}
else
{
end = middle - 1;
}
}
return -1;
}
//递归算法下的二分查找
int binarySearchByRecursion(int arr[], int findData, int start, int end)
{
if (arr == nullptr || start > end)
return -1;
int mid = start + (end - start) / 2;
if (arr[mid] == findData)
return mid;
else if (arr[mid] > findData)
{
return binarySearchByRecursion(arr, findData, start, mid - 1);
}
else
{
return binarySearchByRecursion(arr, findData, mid + 1, end);
}
}
