2.0 KiB
2.0 KiB
title | id | challengeType |
---|---|---|
Averages-Mode | 594d8d0ab97724821379b1e6 | 5 |
Description
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriate or possible to support an unspecified value type, use integers.
Instructions
Tests
tests:
- text: <code>mode</code> is a function.
testString: 'assert(typeof mode === "function", "<code>mode</code> is a function.");'
- text: '<code>mode([1, 3, 6, 6, 6, 6, 7, 7, 12, 12, 17])</code> should equal <code>[6]</code>'
testString: 'assert.deepEqual(mode(arr1), [6], "<code>mode([1, 3, 6, 6, 6, 6, 7, 7, 12, 12, 17])</code> should equal <code>[6]</code>");'
- text: '<code>mode([1, 2, 4, 4, 1])</code> should equal <code>[1, 4]</code>.'
testString: 'assert.deepEqual(mode(arr2).sort(), [1, 4], "<code>mode([1, 2, 4, 4, 1])</code> should equal <code>[1, 4]</code>.");'
Challenge Seed
function mode (arr) {
// Good luck!
return true;
}
After Test
console.info('after the test');
Solution
function mode(arr) {
const counter = {};
let result = [];
let max = 0;
// for (const i in arr) {
arr.forEach(el => {
if (!(el in counter)) {
counter[el] = 0;
}
counter[el]++;
if (counter[el] === max) {
result.push(el);
}
else if (counter[el] > max) {
max = counter[el];
result = [el];
}
});
return result;
}