How to find the values being swapped in two different arrays?

[xxllaacckks]

How to find the values being swapped in two different arrays?
and not allowed to use the std library

{2, 3, 6}
{1, 4, 7}

will become

{1, 3, 7}
{2, 4, 6}

With 2 swaps, and the values being swapped are
1 & 2, 6 & 7

So far, I have gotten the swap and counter to work but I cannot seem to figure out how to find the individual values of the elements that are swapped, I can get only one value to show.

Can I get any hints on how to all grab the values? I am not allowed to use any additional libraries except for the input and output streams. Thanks ahead of time.

  int main() {
    int a1[3] = { 2, 3, 6 };
    int a2[3] = { 1, 4, 7 };
    int i;
    int swapcount = 0;
    int swapvalue;

    std::cout << "Before swap:\n" << endl;
    std::cout << "Array 1:\n" << endl;
    for (int i = 0; i < 3; i++) {
        cout << " " << a1[i] << endl;

    }
    std::cout << "Array 2:\n" << endl;
    for (int i = 0; i < 3; i++) {
        std::cout << " " << a2[i] << endl;

    }

    for (int i = 0; i < 3; i++) {
        if (a1[i] % 2 != 1) {
            swapcount++;
            int temp = a1[i];
            a1[i] = a2[i];
            a2[i] = temp;
            swapvalue = i;
        }
    }

    std::cout << "After swap:\n" << endl;
    std::cout << "Array 1:\n" << endl;
    for (int i = 0; i < 3; i++) {
        std::cout << " " << a1[i] << endl;
    }

    std::cout << "Array 2:\n" << endl;
    for (int i = 0; i < 3; i++) {
        std::cout << " " << a2[i] << endl;

    }

    std::cout << "swap count: " << swapcount << endl;
    std::cout << "swap value: " << swapvalue << endl;
}

[Arslan7041]

Your current program is not even outputting a value. Its outputting the index of the array. More specifically, its outputting the final index which was swapped, which happens to be 2.

[Arslan7041]

There are better solutions, but adding a cout statement in the if-statement seems to be a simple one.

#include<iostream>
  using namespace std;
  
  int main() {
    int a1[3] = { 2, 3, 6 };
    int a2[3] = { 1, 4, 7 };
    int i;
    int swapcount = 0;
    int swapvalue;

    std::cout << "Before swap:\n" << endl;
    std::cout << "Array 1:\n" << endl;
    for (int i = 0; i < 3; i++) {
        cout << " " << a1[i] << endl;

    }
    std::cout << "Array 2:\n" << endl;
    for (int i = 0; i < 3; i++) {
        std::cout << " " << a2[i] << endl;

    }

    for (int i = 0; i < 3; i++) {
        if (a1[i] % 2 != 1) {
            swapcount++;
            int temp = a1[i];
            a1[i] = a2[i];
            a2[i] = temp;
            //swapvalue = i;
            cout << endl;
            cout << "The values swapped when i = " << i << " are " << a1[i] << " and " << a2[i] << endl;
        }
    }

    std::cout << "\nAfter swap:\n" << endl;
    std::cout << "Array 1:\n" << endl;
    for (int i = 0; i < 3; i++) {
        std::cout << " " << a1[i] << endl;
    }

    std::cout << "Array 2:\n" << endl;
    for (int i = 0; i < 3; i++) {
        std::cout << " " << a2[i] << endl;

    }

    std::cout << "swap count: " << swapcount << endl;
    //std::cout << "swap value: " << swapvalue << endl;
}

[Arslan7041]

Another solution is to make an array (maybe call it 'swapArray') the size of 6 (since that is the most amount of values that can be swapped). Fill up the array with the swapped values within the if-statement.

Then traverse through the array using a for-loop going up to 2*swapcount (as each swapcount means 2 values being swapped), and cout the values.

[YFGHNG]

If you're able to use std::vector, I'd create a vector, and then push_back() the values that were swapped into the vector every time the swapValue gets called. Then have a for loop that calls on .size() and output the contents of that vector (the contents that got swapped).