Trouble finding the minimum and maximum of an array value - C++

Question

here is the question

1. Write a program that asks the user to enter the number of kilometres run by 10 different people (Person 1, Person 2, ..., Person 10). Use an array to save the input
2. Once the data has been entered, the program must analyse the data and output which person run the most kilometres.
3. Modify the program so that it also shows which person run the least number of kilometres.

I think I have the algorithm in place based on my code. but the challenge I have is that it returns weird values that obviously never existed in the array.

this is an example of the final answer

how many kilometre did Person 1 run ?
1

how many kilometre did Person 2 run ?
2

how many kilometre did Person 3 run ?
3

how many kilometre did Person 4 run ?
4

how many kilometre did Person 5 run ?
5

how many kilometre did Person 6 run ?
6

how many kilometre did Person 7 run ?
7

how many kilometre did Person 8 run ?
8

how many kilometre did Person 9 run ?
9

how many kilometre did Person 10 run ?
10

The Person with the longest distance is Person 10 and he / she covered a distance of 10 km

The Person with the shortest distance is Person 32767 and he / she covered a distance of 10 km

Here is my code:

#include <iostream>

using namespace std;

class kilometer_sort
{
    // This method / function helps collect
    // all user input of all distance ran by
    // every persons 1-10
public:
    void collect_user_input()
    {
        int no_of_persons = 10;
        int array_of_persons_speed[no_of_persons];
        int person_kilometre;
        for (int b = 0; b < no_of_persons; b++)
        {
            cout << "how many kilometre did Person " << b + 1 << " run ?\n";
            cin >> person_kilometre;
            array_of_persons_speed[b] = person_kilometre;
        }

        check_for_longest_distance(no_of_persons, array_of_persons_speed);
        check_for_shortest_distance(no_of_persons, array_of_persons_speed);
    }

    int person_with_longest_distance_array_index, person_with_shortest_distance_array_index;

public:
    void check_for_longest_distance(int n, int array_of_persons_speed[])
    {
        int highest_no;
        int longest_dist;
        for (int i = 1; i < n; i++)
        {
            if (array_of_persons_speed[i] > array_of_persons_speed[0])
            {
                longest_dist = array_of_persons_speed[i];
                person_with_longest_distance_array_index = i;
            }
        }

        cout << "The Person with the longest distance is Person "
             << person_with_longest_distance_array_index + 1
             << " and he / she covered a distance of "
             << longest_dist
             << " km\n\n";
    }

public:
    void check_for_shortest_distance(int n, int array_of_persons_speed[])
    {
        int highest_no;
        int shortest_distance;
        for (int i = 1; i < n; i++)
        {
            if (array_of_persons_speed[i] < array_of_persons_speed[0])
            {
                shortest_distance = array_of_persons_speed[i];
                person_with_shortest_distance_array_index = i;
            }
        }

        cout << "The Person with the shortest distance is Person "
             << person_with_shortest_distance_array_index + 1
             << " and he / she covered a distance of "
             << shortest_distance
             << " km\n\n";
    }
};

int main()
{
    // Instantiate Class that sort distance
    kilometer_sort ks;

    ks.collect_user_input();

    return false;
}

I will appreciate if someone can help.

Answer 1

The condition of this line is never true for your inputs:

if (array_of_persons_speed[i] < array_of_persons_speed[0])

As a result the person_with_shortest_distance_array_index is never set.

So the value you are outputting is the contents of an uninitialized value (plus one)

You could try using std::max_element and std::min_element or get both at the same time with std::minmax_element instead.

Answer 2

You just need to take care of your internal variable denoting max/min amount as follows:

public:
    void check_for_longest_distance(int n, int array_of_persons_speed[])
    {
        int longest_dist = array_of_persons_speed[0];
        for (int i = 1; i < n; i++)
        {
            if (array_of_persons_speed[i] > longest_dist)
            {
                longest_dist = array_of_persons_speed[i];
                person_with_longest_distance_array_index = i;
            }
        }

        cout << "The Person with the longest distance is Person "
             << person_with_longest_distance_array_index + 1
             << " and he / she covered a distance of "
             << longest_dist
             << " km\n\n";
    }

    void check_for_shortest_distance(int n, int array_of_persons_speed[])
    {
        int shortest_distance = array_of_persons_speed[0]
        for (int i = 1; i < n; i++)
        {
            if (array_of_persons_speed[i] < shortest_distance)
            {
                shortest_distance = array_of_persons_speed[i];
                person_with_shortest_distance_array_index = i;
            }
        }

        cout << "The Person with the shortest distance is Person "
             << person_with_shortest_distance_array_index + 1
             << " and he / she covered a distance of "
             << shortest_distance
             << " km\n\n";
    }