Remove Element

Question

• leetcode: (27) Remove Element | LeetCode OJ
• lintcode: (172) Remove Element

Given an array and a value, remove all occurrences of that value in place and return the new length.

The order of elements can be changed, and the elements after the new length don't matter.

Example
Given an array [0,4,4,0,0,2,4,4], value=4

return 4 and front four elements of the array is [0,0,0,2]

• reference
• visualization

class Solution:
    # @param    A       a list of integers
    # @param    elem    an integer, value need to be removed
    # @return an integer
    # clrs qsort
    def removeElement(self, A, elem):
        j = len(A)-1
        for i in range(len(A) - 1, -1, -1):
            if A[i] == elem:
                A[i], A[j] = A[j], A[i]
                j -= 1
        return j+1