Move Zeroes
Given an array of integers, move all the zeroes to the end of the array while maintaining the relative order of the non-zero elements.
Constraints:
- 1 <= nums.length <= 10^4
- -2^31 <= nums[i] <= 2^31 - 1
Examples:
Input: [0,1,0,3,12]
Output: [1,3,12,0,0]
Explanation: The non-zero elements are moved to the front of the array, and the zeroes are moved to the end.
Solutions
Two Pointers
Time: O(n)Space: O(1)
We use two pointers, i and j, to traverse the array. If the current element is non-zero, we swap it with the element at index j and increment j. This way, all non-zero elements are moved to the front of the array, and the zeroes are moved to the end.
public void moveZeroes(int[] nums) {
int j = 0;
for (int i = 0;
i < nums.length;
i++) {
if (nums[i] != 0) {
int temp = nums[j];
nums[j] = nums[i];
nums[i] = temp;
j++;
}
}
}Follow-up:
What if we want to move all the zeroes to the beginning of the array instead of the end?
