freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-313-sliding-game.english.md

id, challengeType, title

id	challengeType	title
5900f4a61000cf542c50ffb8	5	Problem 313: Sliding game

Description

In a sliding game a counter may slide horizontally or vertically into an empty space. The objective of the game is to move the red counter from the top left corner of a grid to the bottom right corner; the space always starts in the bottom right corner. For example, the following sequence of pictures show how the game can be completed in five moves on a 2 by 2 grid.

Let S(m,n) represent the minimum number of moves to complete the game on an m by n grid. For example, it can be verified that S(5,4) = 25.

There are exactly 5482 grids for which S(m,n) = p2, where p < 100 is prime.

How many grids does S(m,n) = p2, where p < 106 is prime?

Instructions

Tests

tests:
  - text: <code>euler313()</code> should return 2057774861813004.
    testString: assert.strictEqual(euler313(), 2057774861813004, '<code>euler313()</code> should return 2057774861813004.');

Challenge Seed

function euler313() {
  // Good luck!
  return true;
}

euler313();

Solution

// solution required