[LintCode] Move Zeroes 移动零

Posted 2020-07-17 Grandyang

 

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.

Notice

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

 

Example

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

 

LeetCode上的原题，请参见我之前的博客Move Zeroes。

 

解法一：

class Solution {
public:
    /**
     * @param nums an integer array
     * @return nothing, do this in-place
     */
    void moveZeroes(vector<int>& nums) {
        for (int i = 0, j = 0; i < nums.size(); ++i) {
            if (nums[i]) {
                swap(nums[i], nums[j++]);
            }
        }
    }
};

 

解法二：

class Solution {
public:
    /**
     * @param nums an integer array
     * @return nothing, do this in-place
     */
    void moveZeroes(vector<int>& nums) {
        int left = 0, right = 0;
        while (right < nums.size()) {
            if (nums[right]) {
                swap(nums[left++], nums[right]);
            }
            ++right;
        }
    }
};