C++ Sorting an array

Question

I'm following a set of beginner assignments I found on a forum for c++, but I'm totally stuck at a task now. The task is as follows:

Write a program that asks the user to enter the number of pancakes eaten for breakfast by 10 different people (Person 1, Person 2, ..., Person 10) Once the data has been entered the program must analyze the data and output which person ate the most pancakes for breakfast.

★ Modify the program so that it also outputs which person ate the least number of pancakes for breakfast.

★★★★ Modify the program so that it outputs a list in order of number of pancakes eaten of all 10 people.

Now I've sorted out the original bit and the one star bit, however I chose to make it a bit more difficult for myself and not just go with "Person 1, 2, 3, 4 and so on, instead I've assigned names to the characters, and I print it out with a switch. Here's my current code, I'd love some suggestions on how I could sort the array without messing with the order of the numbers in the array, as that would mess up my naming code I guess.

Here's my code, I know it's not the prettiest code out there but it's functional for now.

#include "stdafx.h"
#include <iostream>
using namespace std;

int main()
{
    int nMostPancakesName;
    int nLeastPancakesName;
    enum BreakfastNames
    {
        NED, // 0
        ARYA, // 1
        JON, // 2
        ROBB, // 3
        SANSA, // 4
        CATELYN, // 5
        BRAN, // 6
        THEON, // 7
        HODOR, // 8
        GHOST // 9
    };

    int anArray[10];
    cout << "Enter the number of pancakes Ned ate for breakfast: " << endl;
    cin >> anArray[NED];
    cout << "How many did Arya eat?" << endl;
    cin >> anArray[ARYA];
    cout << "And Jon?" << endl;
    cin >> anArray[JON];
    cout << "What about Robb?" << endl;
    cin >> anArray[ROBB];
    cout << "Did Sansa have any?" << endl;
    cin >> anArray[SANSA];
    cout << "Catelyn?" << endl;
    cin >> anArray[CATELYN];
    cout << "Crippleboy aka Bran?" << endl;
    cin >> anArray[BRAN];
    cout << "The traitor didn't get any, did he?" << endl;
    cin >> anArray[THEON];
    cout << "Hodor?" << endl;
    cin >> anArray[HODOR];
    cout << "No pets at the dining table, Ghost." << endl;
    cin >> anArray[GHOST];

    int nMaxPancakes = 0;
    for (int nPancakes = 0; nPancakes < 10; nPancakes++)
        if (anArray[nPancakes] > nMaxPancakes)
        {
            nMostPancakesName = nPancakes;
            nMaxPancakes = anArray[nPancakes];
        }


    int nLeastPancakes = 100;
    for (int nPancakes2 = 0; nPancakes2 < 10; nPancakes2++)
        if (anArray[nPancakes2] < nLeastPancakes)
        {
            nLeastPancakesName = nPancakes2;
            nLeastPancakes = anArray[nPancakes2];
        }

        for (int nStartIndex = 0; nStartIndex < 10; nStartIndex++)
        {
            int nSmallestIndex = nStartIndex;

            for (int nCurrentIndex = nStartIndex + 1; nCurrentIndex < 10; nCurrentIndex++)
            {
                if (anArray[nCurrentIndex] < anArray[nSmallestIndex])
                    nSmallestIndex = nCurrentIndex;
            }


        }


    switch(nMostPancakesName)
    {
    case 0:
        cout << "Ned had " << nMaxPancakes << endl;
        break;
    case 1:
        cout << "Arya had " << nMaxPancakes << endl;
        break;
    case 2:
        cout << "Jon had " << nMaxPancakes << endl;
        break;
    case 3:
        cout << "Robb had " << nMaxPancakes << endl;
        break;
    case 4:
        cout << "Sansa had " << nMaxPancakes << endl;
        break;
    case 5:
        cout << "Catelyn had " << nMaxPancakes << endl;
        break;
    case 6:
        cout << "Bran had " << nMaxPancakes << endl;
        break;
    case 7:
        cout << "Theon had " << nMaxPancakes << endl;
        break;
    case 8:
        cout << "Hodor had " << nMaxPancakes << endl;
        break;
    case 9:
        cout << "Ghost had " << nMaxPancakes << endl;
        break;
    }

    switch(nLeastPancakesName)
    {
    case 0:
        cout << "Ned had " << nLeastPancakes << endl;
        break;
    case 1:
        cout << "Arya had " << nLeastPancakes << endl;
        break;
    case 2:
        cout << "Jon had " << nLeastPancakes << endl;
        break;
    case 3:
        cout << "Robb had " << nLeastPancakes << endl;
        break;
    case 4:
        cout << "Sansa had " << nLeastPancakes << endl;
        break;
    case 5:
        cout << "Catelyn had " << nLeastPancakes << endl;
        break;
    case 6:
        cout << "Bran had " << nLeastPancakes << endl;
        break;
    case 7:
        cout << "Theon had " << nLeastPancakes << endl;
        break;
    case 8:
        cout << "Hodor had " << nLeastPancakes << endl;
        break;
    case 9:
        cout << "Ghost had " << nLeastPancakes << endl;
        break;
    }

    return 0;
}

Does it have to be an array? You can use a std::vector and sort() via . — ChiefTwoPencils, May 19 '13 at 18:41
@C. Lang, then you would use a map, and answer all the questions with the same program. — 7stud, May 19 '13 at 18:42
See "How to use std::sort to sort an array in C++": http://stackoverflow.com/questions/5897319/how-to-use-stdsort-to-sort-an-array-in-c — Jimbo, May 19 '13 at 18:42
@7stud: good point! I read the title and went to typing:( The vector part was because that's what everyone suggests when OP uses arrays. The one time I do it, I get caught sleepin'. — ChiefTwoPencils, May 19 '13 at 18:45
@C.Lang Well, it doesn't really, it was just the only way I knew how to achieve what the task asked for, so that's what I went for. Haven't come very far in the c++ class yet. I'll look into vectors. — Jon, May 19 '13 at 18:48

score 1 · Answer 1 · answered May 19 '13 at 19:23

Here's a quick example. There are better way's to do this, but this should give you a basic idea of one of the way's to do this.

int score[10];
int ScoreCheck = 0;

// initalize the array "score"
for (ScoreCheck = 0; ScoreCheck < 10; ScoreCheck++)
{
    score[ScoreCheck] = ScoreCheck; // just put everone somewhere
}

ScoreCheck = 0;
while ( ScoreCheck < 9 ) // check to see if we've reached the last person
{
    // check to see if the person lower on the chart ate more
    if ( anArray[score[ScoreCheck]] < anArray[score[ScoreCheck+1]] )
    {
        // swap person 1 and 2, since 2 ate more that 1
        int tmp = score[ScoreCheck];
        score[ScoreCheck]   = score[ScoreCheck+1];
        score[ScoreCheck+1] = tmp;

        // now go back to the beggining to make
        // sure they are in order from begining to end
        ScoreCheck = 0;
        continue;
    }

    // nope, it's in order so far
    // increment to the next person on the chart
    ScoreCheck++
}

See my post above, the sorting's solved. I'm having trouble printing it out with the names though. — Jon, May 19 '13 at 19:40

score 1 · Answer 2 · edited May 23 '17 at 11:57

The answer by Wolfgang Skyler describes a sorting algorithm. You need a minor addition to the algorithm: something that remembers how the elements were swapped. One easy-to-understand solution is an additional array that starts sorted, and gets permuted in exactly the same way as the score array:

BreakfastNames names[] = {
    NED, // 0
    ARYA, // 1
    JON, // 2
    ROBB, // 3
    SANSA, // 4
    CATELYN, // 5
    BRAN, // 6
    THEON, // 7
    HODOR, // 8
    GHOST // 9
};

// Code by Wolfgang Skyler goes here
    ...
    // swap person 1 and 2, since 2 ate more that 1
    int tmp = score[ScoreCheck];
    score[ScoreCheck]   = score[ScoreCheck+1];
    score[ScoreCheck+1] = tmp;

    BreakfastNames tmp1 = names[ScoreCheck];
    names[ScoreCheck]   = names[ScoreCheck+1];
    names[ScoreCheck+1] = tmp1;
    ...

It is also possible to adapt your solution even though you don't implement the sorting algorithm. To do it, use the third parameter of std::sort so it sorts the array names but compares the data in scores:

struct MyComparison
{
    ...
    bool operator()(BreakfastNames name1, BreakfastNames name2)
    {
        ...
        return whatever1 < whatever2;
    }
};

sort(names, names + 10, MyComparison(scores));

score 0 · Answer 3 · answered May 19 '13 at 19:22

So I've sorted most of it with the following code:

sort(anArray, anArray + 10);

for(int ooo=0; ooo < 10; ooo++)
{
    cout << anArray[ooo] << endl;
}

Now the question is how I would solve it to get the names next to the results. I'm feeling like I should go back and make the array multi dimensional, so I'd get a set value for the name as well as the number of pancakes eaten, would this be a good way to go about it or would you recommend something else?

C++ Sorting an array

3 Answers3