moveZeroes.swift

//
//  moveZeroes.swift
//  
//
//  Created by Dong, Anyuan (133) on 2019/4/5.
//

import Foundation
/*
 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.
 https://leetcode.com/problems/move-zeroes/
 */

func moveZeroes(_ nums: inout [Int]) {
    var lastNonZeroFoundAt = 0
    for i in 0 ..< nums.count {
        if nums[i] != 0 {
            nums[lastNonZeroFoundAt] = nums[i]
            lastNonZeroFoundAt = lastNonZeroFoundAt + 1
        }
    }
    for i in lastNonZeroFoundAt ..< nums.count {
        nums[i] = 0
    }
}