foodles.ts

function getHighestFrequencies(sentence: string, n: number) {
    const words = sentence.split(/ +/)

    const frequencyByWord: Record<string, number> = {}

    for (const word of words) {
        frequencyByWord[word] = (frequencyByWord[word] || 0) + 1
    }

    const entries = Object.entries(frequencyByWord)

    entries.sort((a, b) => {
        const aWord = a[0]
        const aFrequency = a[1]
        const bWord = b[0]
        const bFrequency = b[1]

        // Attempt sorting by frequency.

        const frequencyDiff = bFrequency - aFrequency

        if (frequencyDiff !== 0) {
            return frequencyDiff
        }

        // Otherwise sort by alphabetical order.

        const wordDiff = aWord.localeCompare(bWord)

        return wordDiff
    })

    return entries.slice(0, n)
}

function deepAssert(name: string, received: unknown, expected: unknown) {
    const stringifiedA = JSON.stringify(received)
    const stringifiedB = JSON.stringify(expected)

    console.group(name)
    if (stringifiedA !== stringifiedB) {
        console.error(`FAIL\nExpected: ${expected}\nReceived: ${received}`)
    } else {
        console.info("OK")
    }
    console.groupEnd()
}

deepAssert(
    "Base",
    getHighestFrequencies("a", 1),
    [["a", 1]],
)
deepAssert(
    "Excessive spacing",
    getHighestFrequencies("a  b", 3),
    [["a", 1], ["b", 1]],
)
deepAssert(
    "Sliced result",
    getHighestFrequencies("a b", 1),
    [["a", 1]],
)
deepAssert(
    "Not enough words",
    getHighestFrequencies("a", 2),
    [["a", 1]],
)
deepAssert(
    "Multiple-character word",
    getHighestFrequencies("ab", 1),
    [["ab", 1]],
)
deepAssert(
    "Frequency sorting",
    getHighestFrequencies("one three three three two two", 3),
    [["three", 3], ["two", 2], ["one", 1]],
)
deepAssert(
    "Alphabetical sorting",
    getHighestFrequencies("a c b", 3),
    [["a", 1], ["b", 1], ["c", 1]],
)
deepAssert(
    "Frequency sorting over alphabetical sorting",
    getHighestFrequencies("a b b", 2),
    [["b", 2], ["a", 1]],
)
deepAssert(
    "Mix",
    getHighestFrequencies("bar baz foo foo zblah zblah zblah baz toto bar", 3),
    [["zblah", 3],["bar", 2],["baz", 2]],
)