LeetCode move zeroes

Given an array nums, write a function to move all 0‘s to the end of it while maintaining the relative order of the non-zero elements.

For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].


  1. You must do this in-place without making a copy of the array.
  2. Minimize the total number of operations.

We can use a pointer zeroIndex to always point to the index of the first 0. We scan the array, if we encounter a non-zero element, we exchange it with the first 0 that was pointed by zeroIndex, and increase the zeroIndex by 1.  This idea has been applied to solve the color sort problem and remove elements problem