Skip to content
Programming101
Programmingoneonone

Learn everything about programming

  • Home
  • CS Subjects
    • IoT – Internet of Things
    • Digital Communication
    • Human Values
  • Programming Tutorials
    • C Programming
    • Data structures and Algorithms
    • 100+ Java Programs
    • 100+ C Programs
  • HackerRank Solutions
    • HackerRank Algorithms Solutions
    • HackerRank C problems solutions
    • HackerRank C++ problems solutions
    • HackerRank Java problems solutions
    • HackerRank Python problems solutions
Programming101
Programmingoneonone

Learn everything about programming

HackerRank Zig Zag Sequence problem solution

YASH PAL, 31 July 2024

In this HackerRank Zig Zag Sequence problem solution, the task is to debug the existing code to successfully execute all provided test files.

Given an array of n distinct integers, transform the array into a zig-zag sequence by permuting the array elements. A sequence will be called a zig-zag sequence if the first k elements in the sequence are in increasing order and the last k elements are in decreasing order, where k = (n + 1)/2. You need to find the lexicographically smallest zig-zag sequence of the given array.

HackerRank Zig Zag Sequence problem solution

Problem solution in Python.

def findZigZagSequence(a, n):
    a.sort()
    mid = int(n / 2)
    a[mid], a[n-1] = a[n-1], a[mid]

    st = mid + 1
    ed = n - 2
    while(st <= ed):
        a[st], a[ed] = a[ed], a[st]
        st = st + 1
        ed = ed - 1

    for i in range (n):
        if i == n-1:
            print(a[i])
        else:
            print(a[i], end = ' ')
    return

test_cases = int(input())
for cs in range (test_cases):
    n = int(input())
    a = list(map(int, input().split()))
    findZigZagSequence(a, n)

Problem solution in Java.

import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;
public class Main {
    
    public static void main (String[] args) throws java.lang.Exception {
        Scanner kb = new Scanner(System.in);
        int test_cases = kb.nextInt();
        for(int cs = 1; cs <= test_cases; cs++){
            int n = kb.nextInt();
             int a[] = new int[n];
            for(int i = 0; i < n; i++){
                a[i] = kb.nextInt();
            }
            findZigZagSequence(a, n);
        }
   }
   
    public static void findZigZagSequence(int [] a, int n){
        Arrays.sort(a);
        int mid = n/2;
        int temp = a[mid];
        a[mid] = a[n - 1];
        a[n - 1] = temp;
    
        int st = mid + 1;
        int ed = n - 2;
        while(st <= ed){
            temp = a[st];
            a[st] = a[ed];
            a[ed] = temp;
            st = st + 1;
            ed = ed - 1;
        }
        for(int i = 0; i < n; i++){
            if(i > 0) System.out.print(" ");
            System.out.print(a[i]);
        }
        System.out.println();
    }
}


Problem solution in C++.

#include <bits/stdc++.h>
using namespace std;

void findZigZagSequence(vector < int > a, int n){
    sort(a.begin(), a.end());
    int mid = (n + 1)/2 - 1; //change 1
    swap(a[mid], a[n-1]);

    int st = mid + 1;
    int ed = n - 2; //change 2
    while(st <= ed){
        swap(a[st], a[ed]);
        st = st + 1;
        ed = ed - 1; //change 3
    }
    for(int i = 0; i < n; i++){
        if(i > 0) cout << " ";
        cout << a[i];
    }
    cout << endl;
}

int main() {
    int n, x;
    int test_cases;
    cin >> test_cases;

    for(int cs = 1; cs <= test_cases; cs++){
        cin >> n;
        vector < int > a;
        for(int i = 0; i < n; i++){
            cin >> x;
            a.push_back(x);
        }
        findZigZagSequence(a, n);
    }
}

coding problems solutions interview prepration kit

Post navigation

Previous post
Next post
  • Automating Image Format Conversion with Python: A Complete Guide
  • HackerRank Separate the Numbers solution
  • How AI Is Revolutionizing Personalized Learning in Schools
  • GTA 5 is the Game of the Year for 2024 and 2025
  • Hackerrank Day 5 loops 30 days of code solution
How to download udemy paid courses for free

Pages

  • About US
  • Contact US
  • Privacy Policy

Programing Practice

  • C Programs
  • java Programs

HackerRank Solutions

  • C
  • C++
  • Java
  • Python
  • Algorithm

Other

  • Leetcode Solutions
  • Interview Preparation

Programming Tutorials

  • DSA
  • C

CS Subjects

  • Digital Communication
  • Human Values
  • Internet Of Things
  • YouTube
  • LinkedIn
  • Facebook
  • Pinterest
  • Instagram
©2025 Programmingoneonone | WordPress Theme by SuperbThemes