1295-find-numbers-with-even-number-of-digits.js

// 1295. Find Numbers with Even Number of Digits
// https://leetcode.com/problems/find-numbers-with-even-number-of-digits/

/*

Given an array nums of integers, return how many of them contain an even number
of digits.

## Constraints
- 1 <= nums.length <= 500
- 1 <= nums[i] <= 10^5

*/

import { strictEqual } from 'assert';

// 〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰

// Runtime: 60 ms, faster than 60.98% of JavaScript online submissions
// Memory Usage: 34.4 MB, less than 100.00% of JavaScript online submissions

// /**
//  * @param {number[]} nums
//  * @return {number}
//  */
// const findNumbers = nums =>
//   nums.filter(n =>
//     10 ** 5 <= n
//       ? true
//       : 10 ** 4 <= n
//       ? false
//       : 10 ** 3 <= n
//       ? true
//       : 10 ** 2 <= n
//       ? false
//       : 10 <= n
//       ? true
//       : false,
//   ).length;

// 〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰

// Runtime: 92 ms, faster than 10.76% of JavaScript online submissions
// Memory Usage: 39.7 MB, less than 27.80% of JavaScript online submissions

// /**
//  * @param {number[]} nums
//  * @return {number}
//  */
// const findNumbers = nums =>
//   nums.reduce((acc, curr) => acc + +(1 <= Math.log10(curr) % 2), 0);

// 〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰

// Runtime: 96 ms, faster than 7.73% of JavaScript online submissions
// Memory Usage: 40.2 MB, less than 16.25% of JavaScript online submissions

/**
 * @param {number[]} nums
 * @return {number}
 */
const findNumbers = nums =>
  nums.reduce((acc, curr) => acc + (1 <= Math.log10(curr) % 2), 0);

// 〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰〰

// Example 1:
strictEqual(findNumbers([12, 345, 2, 6, 7896]), 2);
// Explanation:
// 12 contains 2 digits (even number of digits).
// 345 contains 3 digits (odd number of digits).
// 2 contains 1 digit (odd number of digits).
// 6 contains 1 digit (odd number of digits).
// 7896 contains 4 digits (even number of digits).
// Therefore only 12 and 7896 contain an even number of digits.

// Example 2:
strictEqual(findNumbers([555, 901, 482, 1771]), 1);
// Explanation:
// Only 1771 contains an even number of digits.