public static int sockMerchant(int n, List<Integer> ar) {
        // 1 2 3 4 1 2 3 4
        int totalPairs = 0;
        int[] colorDistinct = new int[0];
        for (int i = 0; i < n; i++) {
            int sock = ar.get(i);
            int pair = 0;
            for (int j = i; j < n; j++) {
                if (ar.get(j) == sock && !isColorCounted(sock, colorDistinct)) {
                    pair++;
                }
            }
            totalPairs += pair / 2;
            colorDistinct = addColor(sock, colorDistinct);
        }
        return totalPairs;
    }
    
    private static boolean isColorCounted(int sock, int[] colorDistinct) {
        for (int color : colorDistinct) {
            if (color == sock) {
                return true;
            }
        }
        return false;
    }
    
    private static int[] addColor(int sock, int[] colorDistinct) {
        int[] newDistinct = new int[colorDistinct.length + 1];
        for (int i = 0; i < colorDistinct.length; i++) {
            newDistinct[i] = colorDistinct[i];
        }
        newDistinct[colorDistinct.length] = sock;
        return newDistinct;
    }