#include<vector>
#include<iostream>

using namespace std;

vector<int> modes(vector<int>);
int largest(int*,int);

int main() {
    vector<int> nums;
    while(true) {
        int num;
        cout << "Enter a number between 1-20. (Input -1 to stop.)\n> ";
        cin >> num;
        if (num == -1) {
            break;
        } else {
            nums.push_back(num);
        }
    }
    vector<int> mosts = modes(nums);
    for (int i = 0;i < mosts.size();i++) {
        cout << "Found a mode: " << mosts[i]+1 << endl;
    }
}

vector<int> modes(vector<int> nums) {
    int length = nums.size();
    int amounts[20] = {};
    for (int i = 0;i < 20;i++) {
        amounts[i] = 0;
    }
    for (int j = 0;j < nums.size();j++) {
        int num = nums[j];
        amounts[num] += 1;
    }
    for (int i = 0;i < 20;i++) {
        int amount = amounts[i];
        cout << "amount for " << i+1 << ": " << amount << endl;
    }
    int most = largest(amounts,20);
    cout << most << endl;
    vector<int> mosts;
    for (int i = 0;i < 20;i++) {
        int amount = amounts[i];
        if (amount == most) {
                cout << "found one" << endl;
            mosts.push_back(i);
        }
    }
    return mosts;
}

int largest(int arr[], int n)
{
    int i;

    // Initialize maximum element
    int max = arr[0];

    // Traverse array elements
    // from second and compare
    // every element with current max
    for (i = 1; i < n; i++)
        if (arr[i] > max)
            max = arr[i];

    return max;
}