[코테 풀이] N-Repeated Element in Size 2N Array

Q_961) N-Repeated Element in Size 2N Array

출처 : https://leetcode.com/problems/n-repeated-element-in-size-2n-array/

class Solution {
    public int repeatedNTimes(int[] nums) {
        int n = nums.length / 2;
        Map<Integer, Integer> map = new HashMap<>();
        for (int i = 0; i < nums.length; i++) {
            if (!map.containsKey(nums[i])) {
                map.put(nums[i], 1);
            } else {
                map.put(nums[i], map.get(nums[i]) + 1);
            }
        }
        Iterator<Integer> it = map.keySet().iterator();
        while (it.hasNext()) {
            int next = it.next();
            if (map.get(next) == n) return next;
        }
        return -1;
    }
}