C++K3

#include <iostream>
#include <iomanip>

using namespace std;

struct Rat
{
    string name;
    int age;
    bool isRatted;
};

void readRat(Rat& r)
{
    cout << "Rat name: ";
    cin.ignore();
    getline(cin, r.name);
    cout << "Rat age: ";
    cin >> r.age;
    cout << "Rat isRatted (0/1): ";
    int num;
    cin >> num;
    if (num == 0)
    {
        r.isRatted = false;
    }
    else
    {
        r.isRatted = true;
    }
}

void printRat(Rat& r)
{
    cout << "Rat info: " << endl;
    cout << "Rat name: " << r.name << endl;
    cout << "Rat age: " << r.age << endl;
    cout << boolalpha << "Rat isratted: " << r.isRatted << endl;
}
const int SIZE = 20;

void readRatArr(Rat ratarr[], int n)
{
    for (int i = 0; i < n; i++)
    {
        readRat(ratarr[i]);
    }
}

void printRatArr(Rat ratarr[], int n)
{
    for (int i = 0; i < n; i++)
    {
        printRat(ratarr[i]);
    }
}

void swapRats(Rat& r1, Rat& r2)
{
    Rat temp = r1;
    r1 = r2;
    r2 = temp;
}


void selectionSort(Rat rarr[], int n)
{
    int i, j, min_idx;

    // One by one move boundary of unsorted subarray
    for (int i = 0; i < n-1; i++)
    {
        // Find the minimum element in unsorted array
        min_idx = i;
        for (int j = i+1; j < n; j++)
        if (rarr[j].age < rarr[min_idx].age)
            min_idx = j;

        // Swap the found minimum element with the first element
        swapRats(rarr[min_idx], rarr[i]);
    }
}

void enterMatrix(int a[][SIZE], int n, int m)
{
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            cin >> a[i][j];
        }
    }
}

void printMatrix(int a[][SIZE], int n, int m)
{
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            cout << setw(3) << a[i][j];
        }
        cout << endl;
    }
}

int sumMatrix(int a[][SIZE], int n, int m)
{
    int sum = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
          sum += a[i][j];
        }
    }
    return sum;
}

int fib(int n)
{
    if (n == 0 || n == 1)
    {
        return 1;
    }
    return fib(n - 2) + fib(n - 1);
}


int digitSum (int number)
{
    if (number == 0)
    {
        return 0;
    }
    return (number % 10) + digitSum(number / 10);
}

int digitRoot(int number)
{
    if (number < 10)
    {
        return number;
    }
    digitRoot(digitSum(number));
}

int main()
{
   /* int n = 3;
    int m = 4;
    int matrix[SIZE][SIZE];
    enterMatrix(matrix, n, m);
    printMatrix(matrix, n, m);
    cout << "Sum = " << sumMatrix(matrix, n, m) <<endl;
    */
    cout << digitRoot(31198) << endl;
    return 0;
}