TopKFrequentElements.go

func topKFrequent(nums []int, k int) []int {
    cnt := make(map[int]int)
    idx := make(map[int]int)
    res := []int{}
    
    for _, x := range nums {
        cnt[x]++
        if cnt[x] != 1 {
            moveTo := -1
            for i:=idx[x]-1; i>=0; i-- {
                if cnt[res[i]] < cnt[x] {
                    moveTo = i
                    idx[res[i]]++
                } else {
                    break
                }
            }
            
            if moveTo != -1 {
                tmp := []int{}
                for _, n := range res[:moveTo] {
                    tmp = append(tmp, n)
                }
                tmp = append(tmp, x)
                for _, n := range res[moveTo:] {
                    if n != x {
                        tmp = append(tmp, n)
                    }
                }
                res = tmp
                idx[x] = moveTo
            }
        } else {
            res = append(res, x)
            idx[x] = len(res)-1
        }
    }
    return res[:k]
}