Problem 11. Back and Forth Rows

Created by Cody Team
Appears in Project Euler I

Difficulty:Rate

Solve Later
Add To GroupÃ‚

Given a number n, create an n-by-n matrix in which the integers from 1 to n^2 wind back and forth along the rows as shown in the examples below.

Examples:

 Input  n = 3
 Output a = [ 1 2 3
              6 5 4
              7 8 9 ]

 Input  n = 4
 Output a = [ 1     2     3     4
              8     7     6     5
              9    10    11    12
             16    15    14    13 ]

Solve

Solution Stats

17376 Solutions
6875 Solvers

Last Solution submitted on Mar 14, 2025

Last 200 Solutions

Problem Comments

16 Comments

16 Comments

Show 13 older comments

Sharon Spelt on 8 Nov 2018

It appears a '\r' is needed after the %% in the first test of the solution to make it process properly.

goc3 on 9 Nov 2018

The problem with the first test case has been fixed here.

Aleksandrov Igor on 14 Jan 2020

This code
b=vec2mat(1:n^2,n)
b(2:2:end,:)=fliplr(b(2:2:end,:))
work in Matlab, why it doesn't works on site?

Solution Comments

Show comments

Problem Recent Solvers6875

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 11. Back and Forth Rows

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers6875

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Problem 11. Back and Forth Rows

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers6875

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Players