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].
Note:
You must do this in-place without making a copy of the array.Minimize the total number of operations.思路：顺序遍历数组，每遇到一个非零数字便和前面第一个0进行交换。indexFirstZero记录了第一个0的索引。
转载于:https://www.cnblogs.com/vincent93/p/6686512.html
