Kth最大元素

Question

I am trying to solve the Kth Largest Element problem.I don't why following bugs appeared. "E: 6,16: Undefined variable 'quickSelect' (undefined-variable) E: 27,19: Undefined variable 'quickSelect' (undefined-variable) E: 30,19: Undefined variable 'quickSelect' (undefined-variable)" Here are my codes.

def kthLargestElement(self, k, A):
     return quickSelect(A, 0, len(A) - 1, k)

def quickSelect(self, nums, start, end, k):
    if start == end:
        return nums[start]

    i = start
    j = end
    pivot = (nums[start] + nums[end]) // 2

    while i <= j:
        while i <= j and nums[i] < pivot:
            i += 1
        while i <= j and nums[j] > pivot:
            j -= 1
        if i <=j:
            nums[i], nums[j] = nums[j], nums[i]
            i += 1
            j -= 1

    if start + k - 1 <= j:
        return quickSelect(nums, start, j, k)

    if start + k - 1 >= i:
        return quickSelect(nums, i, end, k - (i - start))

    return nums[j + 1]

Answer 1

Python cannot find quickSelect because it's looking for it in the global namespace rather than looking inside your class. To fix this you can invoke your function using self.quickSelect(...) instead of quickSelect(...) .