LeetCode: 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: You must do this in-place without making a copy of the array. Minimize the total number of operations. Credits: Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.
自己的答案：
public class Solution { public void moveZeroes(int[] nums) { if (nums == null) { return; } int left = -1; for (int i = 0; i < nums.length; i++) { if (nums[i] == 0) { if (left < 0) { left = i; } } else { if (left >= 0) { nums[left] = nums[i]; nums[i] = 0; left++; } } } } }O(N)的答案：
public void moveZeroes(int[] nums) { if (nums == null || nums.length == 0) return; int insertPos = 0; for (int num: nums) { if (num != 0) nums[insertPos++] = num; } while (insertPos < nums.length) { nums[insertPos++] = 0; } }