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.

Example:

Input: [0,1,0,3,12]
Output: [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.

移动零。

题意很直观，将数组中所有0移动到数组的末端。要求必须in-place做。

思路是给一个cur指针和一个i指针，用i去遍历数组。当数组遇到非0的数字的时候，就放到cur的位置，cur++。如果扫描完整个数组cur的位置没有到达数组末尾，后面的位置用0补齐。

时间O(n)

空间O(1)

Java实现

 1 class Solution {
 2     public void moveZeroes(int[] nums) {
 3         int cur = 0;
 4         for (int i = 0; i < nums.length; i++) {
 5             if (nums[i] != 0) {
 6                 nums[cur] = nums[i];
 7                 cur++;
 8             }
 9         }
10         while (cur < nums.length) {
11             nums[cur] = 0;
12             cur++;
13         }
14     }
15 }

 

JavaScript实现

 1 /**
 2  * @param {number[]} nums
 3  * @return {void} Do not return anything, modify nums in-place instead.
 4  */
 5 var moveZeroes = function(nums) {
 6     let cur = 0;
 7     for (let i = 0; i < nums.length; i++) {
 8         if (nums[i] !== 0) {
 9             nums[cur] = nums[i];
10             cur++;
11         }
12     }
13     while (cur < nums.length) {
14         nums[cur] = 0;
15         cur++;
16     }
17 };

 

LeetCode 题目总结