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.
Solution
维护两个 index,一个遍历,一个用来交换值
Complexity
时间复杂度 O(n),空间复杂度 O(1)
Code
public class Solution {
public void moveZeroes(int[] nums) {
int i = -1, j = 0;
while (j < nums.length) {
if (nums[j] != 0) {
swap(++i, j, nums);
}
j++;
}
}
public void swap(int i, int j, int[] nums) {
int temp = nums[i];
nums[i] = nums[j];
nums[j] = temp;
}
}