函数int findMax(int arr[], int low, int high) 计算数组中最大元素，其中数组arr从索引 low到high，（ ）正确实现了分治逻辑。

if (low == high)
return arr[low];
int mid = (low + high) / 2;
return arr[mid];

if (low >= high)
return arr[low];
int mid = (low + high) / 2;
int leftMax = findMax(arr, low, mid - 1);
int rightMax = findMax(arr, mid, high);
return leftMax + rightMax;

if (low > high)
return 0;
int mid = low + (high - low) / 2;
int leftMax = findMax(arr, low, mid);
int rightMax = findMax(arr, mid + 1, high);
return leftMax * rightMax;

if (low == high)
return arr[low];
int mid = low + (high - low) / 2;
int leftMax = findMax(arr, low, mid);
int rightMax = findMax(arr, mid + 1, high);
return (leftMax > rightMax) ? leftMax : rightMax;