283. 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].

Note:

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

人家方法:
扫描数组, 遇非0元素, 送入position的位置. 最后,依据position修改数组末端元素们为0.
\(O(n)\) time, \(O(1)\) extra space.

void moveZeroes(vector<int>& A) {
    int posi = 0, n = A.size();
    for (int i = 0; i < n; i++)
        if (A[i] != 0) A[posi++] = A[i];

    while (posi < n)
        A[posi++] = 0;
}