LeetCode 283.Move Zeroes

Quesiton

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.

Explanation

双指针，遇到不是0的就去找在此之前是0的数。

Code

public class Solution {
    public void moveZeroes(int[] nums) {
        int head = 0;
        if (nums == null || nums.length == 0) return;
        while(head < nums.length) {
            if (nums[head] != 0) {
                for (int i=0; i<head; i++) {
                    if (nums[i] == 0) {
                        int tmp = nums[head];
                        nums[head] = 0;
                        nums[i] = tmp;
                        break;
                    }
                }
            }
            head ++;
        }
    }
}