g0301_0400.s0347_top_k_frequent_elements.solution.ts Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-all Show documentation

104 LeetCode algorithm problem solutions

The newest version!

// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Hash_Table #Sorting
// #Heap_Priority_Queue #Counting #Divide_and_Conquer #Quickselect #Bucket_Sort
// #Data_Structure_II_Day_20_Heap_Priority_Queue #Big_O_Time_O(n*log(n))_Space_O(k)
// #2023_10_04_Time_62_ms_(87.48%)_Space_45.6_MB_(67.84%)

function topKFrequent(nums: number[], k: number): number[] {
    let elementCount = new Array(nums.length)
    let hashMap = new Map()
    let res: number[] = new Array()
    nums.forEach((num) => {
        if (!hashMap.has(num)) hashMap.set(num, 1)
        else hashMap.set(num, hashMap.get(num)! + 1)
    })
    hashMap.forEach((value, key) => {
        if (elementCount[value] === undefined) elementCount[value] = [key]
        else elementCount[value].push(key)
    })
    for (let i = elementCount.length - 1; i >= 0; i--) {
        if (elementCount[i] !== undefined) res.push(...elementCount[i].values())
        if (res.length === k) {
            return res
        }
    }
    return res
}

export { topKFrequent }