Thread: How do I find the mode in a list when values of similar frequencies mean that there is no mode?

My logic in this program was to compare values and store the values with the highest frequencies using maxFreq. If I have two of the same highest frequencies, then the computer should display "No mode", but I got very confused after a while because I might have several modes and I think that I might even have to use extra loops to loop through the frequencies of values to compare the frequencies of the modes.

  public static void printStatistics(ArrayList<Integer> list) {
    double sum = 0;
    double maxFreq = 0;
    int freq = 1;
    for (int i = 0; i < list.size(); i++) {
      sum += list.get(i);
      for (int j = i + 1; j < list.size(); j++) {
        //compare the max freq and freq count
        if (list.get(i) == list.get(j)) {
         freq++;
          if (maxFreq < freq) {
            maxFreq = freq;
            freq = 1;
        } else {
          freq = 1;
        }
      }
    }
  }
}

I have questions on sorting algorithms, traversing 2d arrays to print the sums, moving elements around, and understanding the super keyword/is a-has a relationship/class casting. These areas are making me struggle since I don't understand why my code doesn't work in certain situations.

The assignment requires me to find the sum, average, and mode of a list of integers passed into the array. I can find the average and sum, but not the mode. My code doesn't work when there are two values with the same frequency e.g. 1, 1, 3, 3, 5, 5 (my code would print 5 instead of "There is no mode").

Here's my full code:

public static void printStatistics(ArrayList<Integer> list) {
    int sum = 0;
    int maxFreq = 0;
    int freq = 1;
    boolean noSimilarMode = true;
    ArrayList<Integer> l1 = new ArrayList<Integer>();
    for (int i = 0; i < list.size(); i++) {
      sum += list.get(i);
 
      for (int j = 0; j < list.size(); j++) {
        //compare the max freq and freq count
        if (j == i) {
          continue;
        }
        if (list.get(i) == list.get(j)) {
          freq++;
          if (j < list.size() - 1 && maxFreq < freq && (list.get(j + 1) != list.get(j))) {
            maxFreq = list.get(j);
            l1.add(freq);
            freq = 1;
          }
        } else {
          freq = 1;
        }
          if (maxFreq < freq) {
            maxFreq = list.get(j);
            freq = 1;
          } else {
            freq = 1;
          }
      }
    }
 
    for (int a = 0; a < l1.size(); a++) {
      for (int b = 0; b < l1.size(); b++) {
        if (l1.size() > 1 && (a == b)) {
          continue;
        } else {
          if (l1.get(a) == l1.get(b)) {
            noSimilarMode = false;
            break;
          }
        }
      }
    }
 
    double avg = 1.0 * sum/(list.size()); //avg
    System.out.println();
      // prints
    if (maxFreq > 1 && freq == 1 && noSimilarMode) {
      System.out.println("Sum: " + sum);
      System.out.println("Average: " + avg);
      System.out.println("Mode: " + maxFreq);
    } 
    }*/ else if (noSimilarMode == false || freq == 1) {
      System.out.println("Sum: " + sum);
      System.out.println("Average: " + avg);
      System.out.println("Mode: no single mode");
    }
  }
}