public static long kSub(int k, List<Integer> nums) {

        long currSum = 0;
        long[] sum = new long[nums.size()];
        long count = 0;
        
        Map<Integer, Long> remainderMap = new HashMap<>();
        remainderMap.put(0, 1L);
        
        for(int i = 0 ; i < nums.size(); i++){
            currSum = currSum + nums.get(i);
            sum[i] = currSum;
       
            int remainder = (int)(sum[i] % k);
            
            if(!remainderMap.containsKey(remainder)){
                remainderMap.put(remainder, 1L);
            }else{
                long frequency = remainderMap.get(remainder);
                count = count + frequency;
                remainderMap.put(remainder, frequency + 1); 
            }
            
        }