function frequencySort(nums: number[]): number[] {
const frequent = new Map()
for(const num of nums) frequent.set(num, (frequent.get(num) ?? 0) + 1)
return nums.sort((a, b) => {
const aFreq = frequent.get(a)
const bFreq = frequent.get(b)
if(aFreq !== bFreq) return aFreq - bFreq
return b - a
})
};