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### How to Nail your next Technical Interview

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## You may be missing out on a 66.5% salary hike*

### Nick Camilleri

Head of Career Skills Development & Coaching
*Based on past data of successful IK students
Help us know you better!

## How many years of coding experience do you have?

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## FREE course on 'Sorting Algorithms' by Omkar Deshpande (Stanford PhD, Head of Curriculum, IK)

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# Zigzag Sort Problem Statement

Given a list of numbers, reorder it in `zigzag` order.

Let's say the given list of numbers is `numbers`. `Zigzag` order of `numbers` should follow the following order: `numbers[0] <= numbers[1] >= numbers[2] <= numbers[3]...`.

## Example One

``````{
"numbers": [3, 5, 6, 1, 4, 2]
}
``````

Output:

``````[3, 6, 1, 5, 2, 4]
``````

Explanation: `[2, 5, 3, 4, 1, 6]` is also accepted.

## Example Two

``````{
"numbers": [3, 1, 3, 1, 2, 4]
}
``````

Output:

``````[1, 3, 1, 3, 2, 4]
``````

## Notes

Constraints:

• 1 <= size of the input list <= 2x106
• 10-3 <= any element of the input list <= 103

## Code For Zigzag Sort Solution: One Pass

``````/*
Asymptotic complexity in terms of number of elements \`n\`:
* Time: O(n).
* Auxiliary space: O(1).
* Total space: O(n).
*/

vector<int> zigzag_sort(vector<int> &numbers) {
for (int i = 0; i + 1 < (int)numbers.size(); i++) {
if (i % 2 == 0 && numbers[i] > numbers[i + 1]) {
swap(numbers[i], numbers[i + 1]);
}
else if (i % 2 == 1 && numbers[i] < numbers[i + 1]) {
swap(numbers[i], numbers[i + 1]);
}
}
return numbers;
}

``````

We hope that these solutions to zigzag sort problem have helped you level up your coding skills. You can expect problems like these at top tech companies like Amazon and Google.

If you are preparing for a tech interview at FAANG or any other Tier-1 tech company, register for Interview Kickstart's FREE webinar to understand the best way to prepare.

Interview Kickstart offers interview preparation courses taught by FAANG+ tech leads and seasoned hiring managers. Our programs include a comprehensive curriculum, unmatched teaching methods, and career coaching to help you nail your next tech interview.

We offer 18 interview preparation courses, each tailored to a specific engineering domain or role, including the most in-demand and highest-paying domains and roles, such as:

### Try yourself in the Editor

Note: Input and Output will already be taken care of.

# Zigzag Sort Problem Statement

Given a list of numbers, reorder it in `zigzag` order.

Let's say the given list of numbers is `numbers`. `Zigzag` order of `numbers` should follow the following order: `numbers[0] <= numbers[1] >= numbers[2] <= numbers[3]...`.

## Example One

``````{
"numbers": [3, 5, 6, 1, 4, 2]
}
``````

Output:

``````[3, 6, 1, 5, 2, 4]
``````

Explanation: `[2, 5, 3, 4, 1, 6]` is also accepted.

## Example Two

``````{
"numbers": [3, 1, 3, 1, 2, 4]
}
``````

Output:

``````[1, 3, 1, 3, 2, 4]
``````

## Notes

Constraints:

• 1 <= size of the input list <= 2x106
• 10-3 <= any element of the input list <= 103

## Code For Zigzag Sort Solution: One Pass

``````/*
Asymptotic complexity in terms of number of elements \`n\`:
* Time: O(n).
* Auxiliary space: O(1).
* Total space: O(n).
*/

vector<int> zigzag_sort(vector<int> &numbers) {
for (int i = 0; i + 1 < (int)numbers.size(); i++) {
if (i % 2 == 0 && numbers[i] > numbers[i + 1]) {
swap(numbers[i], numbers[i + 1]);
}
else if (i % 2 == 1 && numbers[i] < numbers[i + 1]) {
swap(numbers[i], numbers[i + 1]);
}
}
return numbers;
}

``````

We hope that these solutions to zigzag sort problem have helped you level up your coding skills. You can expect problems like these at top tech companies like Amazon and Google.

If you are preparing for a tech interview at FAANG or any other Tier-1 tech company, register for Interview Kickstart's FREE webinar to understand the best way to prepare.

Interview Kickstart offers interview preparation courses taught by FAANG+ tech leads and seasoned hiring managers. Our programs include a comprehensive curriculum, unmatched teaching methods, and career coaching to help you nail your next tech interview.

We offer 18 interview preparation courses, each tailored to a specific engineering domain or role, including the most in-demand and highest-paying domains and roles, such as: