[LeetCode 283] Move Zeroes

最新推荐文章于 2025-04-04 09:54:25 发布

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本文介绍了一种使用双指针技术将数组中的所有零元素移至末尾同时保持非零元素相对顺序的方法。通过两个指针分别定位首个零元素和紧随其后的首个非零元素，并进行交换，实现了在原地修改数组的同时最小化操作次数。

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.

solution:

two pointers, one point to first zero element, second point to following first non-zero element.

public class Solution {
    public void moveZeroes(int[] nums) {
        if(nums.length<=1) return;
        int first = 0;
        int sec = 0;
        while(sec<nums.length) {
            //find first zero element
            while(first<nums.length && nums[first] !=0) {
                first++;
            }
            if(first == nums.length) return;
            sec = first+1;
            //find following first non-zero element
            while(sec<nums.length && nums[sec] == 0){
                sec++;
            }
            if(sec == nums.length) return;
            swap(nums, first, sec);
        }
    }
    public void swap(int[] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }
}