1.2 KiB
1.2 KiB
id | challengeType | title | forumTopicId |
---|---|---|---|
5900f5091000cf542c51001b | 5 | Problem 408: Admissible paths through a grid | 302076 |
Description
Consider a path from point (x1, y1) to point (x2, y2) using only unit steps north or east. Let's call such a path admissible if none of its intermediate points are inadmissible.
Let P(n) be the number of admissible paths from (0, 0) to (n, n). It can be verified that P(5) = 252, P(16) = 596994440 and P(1000) mod 1 000 000 007 = 341920854.
Find P(10 000 000) mod 1 000 000 007.
Instructions
Tests
tests:
- text: <code>euler408()</code> should return 299742733.
testString: assert.strictEqual(euler408(), 299742733);
Challenge Seed
function euler408() {
// Good luck!
return true;
}
euler408();
Solution
// solution required