[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].

Note:

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

 

分析：快速排序Partition的应用。时间复杂度O(n),空间复杂度O(1)

class Solution {
public:
    void moveZeroes(vector<int>& nums) {
        if (nums.empty()) return;
        
        int p =  -1;
        int i = 0;
        
        for (; i < nums.size(); i++) {
            if (nums[i] != 0) {
                swap(nums[++p], nums[i]);
            }
        }
    }
};