[Leetcode][Python]27: Remove Element

# -*- coding: utf8 -*-‘‘‘__author__ = ‘[email protected]‘

27: Remove Elementhttps://oj.leetcode.com/problems/remove-element/

Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn‘t matter what you leave beyond the new length.

===Comments by Dabay===一次循环，两个指针，一个指向插入的位置，另外一个一直往前面走。    如果二号指针的数就是需要删除的数，二号指针继续走。    如果不是要删除的数，把二号指针指向的数移到一号指针的位置上，然后两个指针继续走。最后跟新数组，返回长度。‘‘‘

class Solution:    # @param    A       a list of integers    # @param    elem    an integer, value need to be removed    # @return an integer    def removeElement(self, A, elem):        i = j = 0        while j < len(A):            if A[j] != elem:                A[i] = A[j]                i += 1            j += 1        A = A[:i]        return len(A)

def main():    sol = Solution()    print sol.removeElement([1,1,2], 1)

if __name__ == "__main__":    import time    start = time.clock()    main()    print "%s sec" % (time.clock() - start)