C排序解释和麻烦

Question

我无法解决这个问题。我应该排序然后搜索一个数组(通过二进制搜索)，但我在如何获取我认为的数组的大小方面遇到了麻烦。

int binarySearch( int Arr[], int value)
{
  int low = 0;
  int high =sizeof(Arr)/sizeof(int);
  int mid = (low+high)/2;

  printf("%d\n",high);
  while (low <= high && Arr[mid] != value)
    {
      if( Arr[mid] < value)
        {
          low = mid+1;
        }
      else
        {
          high = mid-1;
        }
      mid = (low+high)/2;
    }
  if (low > high)
    {
      mid= -1;
    }
  return mid;
}


int main()
{
  BubbleSort( Array, 10);
  int pos = binarySearch(Array, 3);
  printf("The sorted array is: ");
  PrintArray( Array, 10);
  printf("\n");
  printf("Now lets look for number 3\n");
  printf("The number was located in space %d\n", pos);
  PrintArray( Array, 10);
}

但我一直得到的是:

 ./search
2 \\This is where I wanted to see what I was getting as the size of my array, 2???
The sorted array is: 0 1 2 3 4 5 6 7 8 9
Now lets look for number 3
The number was located in space -1
0 1 2 3 4 5 6 7 8 9

Answer 1

在作为函数参数的数组上使用 sizeof 不会像您预期的那样工作。

当一个数组被传递给一个函数时，它会衰减到一个指向数组第一个元素的指针。

所以这样:

int binarySearch( int Arr[], int value)

与此相同:

int binarySearch( int *Arr, int value)

而sizeof(Arr)与调用sizeof(int *)是一样的。

您需要将数组的大小作为单独的参数传递给您的函数。