为什么我的二分搜索不适用于我的数组？

Question

尝试学习一些基本的数据结构和算法，我尝试编写基本的二分搜索代码，但除非输入与中间相同，否则它不起作用？有人可以帮忙吗？

void Search(int input) {

    int array[10] = { 0.1,2,3,4,5,6,7,8,9,10 };
    int first = array[0];
    int last = sizeof(array) / sizeof(array[0]);;
    int middle = first + last / 2;

    if (input == middle) {
        cout << "search succesful";
    }
    else if (input > middle) {
        middle + 1;
        Search(input);

    }
    else if (input < middle) {
        middle - 1;
        Search(input);

    }
}

  int main()
    {
     int input;
     cin >> input;
     Search(input);
    }

Answer 1

如果您想使用递归，那么您还应该传递数组的左右边框并在 if 语句中更改它们。当你这样做时，middle-1你不会改变任何东西。这是二分查找的实现

int binarySearch(int nums[], int low, int high, int target)
{
    // Base condition (search space is exhausted)
    if (low > high) {
        return -1;
    }
 
    // find the mid-value in the search space and
    // compares it with the target
 
    int mid = (low + high)/2;    // overflow can happen
    // int mid = low + (high - low)/2;
 
    // Base condition (target value is found)
    if (target == nums[mid]) {
        return mid;
    }
 
    // discard all elements in the right search space,
    // including the middle element
    else if (target < nums[mid]) {
        return binarySearch(nums, low, mid - 1, target);
    }
 
    // discard all elements in the left search space,
    // including the middle element
    else {
        return binarySearch(nums, mid + 1, high, target);
    }
}