0560 Subarray Sum Equals K

Question

My Solution: Brute Force

class Solution {
    public int subarraySum(int[] nums, int k) {
        int counter = 0;
        for(int i = 0; i < nums.length; i++){
            int sum = 0;
            for(int j = i; j < nums.length; j++){
                sum += nums[j];
                if(sum == k){
                    counter++;
                }
            }
        }
        return counter;
    }
}

My Solution 2:

class Solution {
    public int subarraySum(int[] nums, int k) {
        Map<Integer, Integer> sums = new HashMap<>();
        sums.put(0,1);

        int sum = 0;
        int count = 0;

        for(int i : nums){
            sum += i;
            count += sums.getOrDefault(sum - k, 0);
            sums.merge(sum, 1, (v1, v2) -> v1 + v2);
        }

        return count;
    }
}