Master LeetCode: How to Shift Zeroes to the Right in Java Efficiently

Introduction

In the world of Data Structures and Algorithms (DSA), solving array manipulation problems is a common task, especially in coding interviews. One frequently encountered problem is shifting all zeroes in an array to the right while maintaining the relative order of non-zero elements. In this blog post, we’ll explore an efficient Java solution to this LeetCode problem, step by step.

Problem Statement

Given an integer array, you need to move all zeroes to the end of the array while keeping the order of non-zero elements intact. For example, given the array [5, 0, 4, 0, 9, 0, 1, 10], the output should be [5, 4, 9, 1, 10, 0, 0, 0].

Understanding the Approach

To tackle this problem efficiently, we will use a two-pointer technique. This approach allows us to rearrange the elements in a single pass through the array, resulting in a time complexity of O(n) and a space complexity of O(1).

Java Solution

Here’s a concise Java implementation of the algorithm:

import java.util.Arrays;

public class ShiftZerosToRight {

	public static void main(String[] args) {
		 int[] arr = {5, 0, 4, 0, 9, 0, 1, 10};
		 
		 shiftZerosToTheRight(arr);
		 
		 System.out.println("Array after zeroes shift: "
                                                    +Arrays.toString(arr));
	}

	private static void shiftZerosToTheRight(int[] arr) {
		if (arr.length==0) {
			return;
		}
		int start = 0;
		
		for (int i=0; i< arr.length; i++) {
			if (arr[i] !=0) {				
				arr[start++] = arr[i];
			}
		}
		
		for (int i = start; i < arr.length; i++) {
			arr[i] = 0;
		}
		
	}
}

Explanation of the Code

Initialization: We start by initializing a pointer start to track the index for non-zero elements.
First Loop: We iterate through the array. Whenever we encounter a non-zero element, we place it at the start index and increment start.
Second Loop: After moving all non-zero elements, we fill the rest of the array with zeroes.

Conclusion

Shifting zeroes to the right is a fundamental problem that not only enhances your understanding of array manipulation but also prepares you for DSA interviews on platforms like LeetCode. By implementing this efficient solution, you can significantly improve your coding skills and problem-solving abilities.

Call to Action

If you found this solution helpful, consider following my journey on LeetCode and DSA topics! Don’t forget to check out my other blog posts for more coding challenges and solutions. Happy coding!

Tags: #LeetCode #Java #DSA #CodingChallenges #ArrayManipulation #Programming #InterviewPrep #CodingInterview #TechInterview #LearnToCode

Master LeetCode: How to Shift Zeroes to the Right in Java Efficiently | DSA