Move Zeroes

LeetCode 283 · View on LeetCode

Same-direction two pointers. The slow pointer tracks where the next non-zero value should go. Swap to keep non-zero order intact and push zeroes to the end.

package main

import "fmt"

func moveZeroes(nums []int) {
	slow := 0
	for fast := 0; fast < len(nums); fast++ {
		if nums[fast] != 0 {
			nums[slow], nums[fast] = nums[fast], nums[slow]
			slow++
		}
	}
}

func main() {
	a := []int{0, 1, 0, 3, 12}
	moveZeroes(a)
	fmt.Println(a) // [1 3 12 0 0]

	b := []int{0, 0, 1}
	moveZeroes(b)
	fmt.Println(b) // [1 0 0]

	c := []int{4, 0, 5, 0, 0, 6}
	moveZeroes(c)
	fmt.Println(c) // [4 5 6 0 0 0]
}