
nums 순회하며 기록set 순회-1 반환function findMaxK(nums: number[]): number {
const set = new Set<number>()
for(const num of nums) {
set.add(num)
}
let maxK = -Infinity
for(const num of set) {
if(!set.has(-num)) continue
maxK = Math.max(maxK, num)
}
if(maxK === -Infinity) return -1
return maxK
};