freeCodeCamp/curriculum/challenges/chinese/08-coding-interview-prep/project-euler/problem-15-lattice-paths.chinese.md

id	challengeType	title	videoUrl	localeTitle
5900f37b1000cf542c50fe8e	5	Problem 15: Lattice paths		问题15：格子路径

Description

从2×2网格的左上角开始，只能向右和向下移动，右下角有6条路线。

通过给定的gridSize有多少这样的路由？

Instructions

Tests

tests:
  - text: <code>latticePaths(4)</code>应该返回70。
    testString: 'assert.strictEqual(latticePaths(4), 70, "<code>latticePaths(4)</code> should return 70.");'
  - text: <code>latticePaths(9)</code>应该返回48620。
    testString: 'assert.strictEqual(latticePaths(9), 48620, "<code>latticePaths(9)</code> should return 48620.");'
  - text: <code>latticePaths(20)</code>应该返回137846528820。
    testString: 'assert.strictEqual(latticePaths(20), 137846528820, "<code>latticePaths(20)</code> should return 137846528820.");'

Challenge Seed

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

latticePaths(4);

Solution

// solution required