Moving values of an array to the right

[Chamat]

I'm having some issues with making a function that moves every value in the array to the right.

the order is coming out messed up, and the last value is coming out as a very strange value.

What's supposed to happen is every value is moved to the right and the first value is replaced by the former last value.

#include <iostream>
#include <cstdlib>
#include <iomanip>
using namespace std;

  void shift(int values[], int size) {
	for (int i = 0; i < size; i++) {
		int temp;
		temp = values[size - 1];
		values[i] = values[i + 1];
		values[0] = temp;
		cout << values[i] << setw(4);
	}
	cout << endl;
}
int main()
{
	cout << "Random 10 index array" << endl;
	const int CAP = 10;
	int numbers[CAP];

	srand(time(0));
	int i;
	for (i = 0; i < CAP; i++) {
		int rng = rand() % 100 + 1;
		numbers[i] = rng;
		cout << numbers[i] << setw(4);

	}
cout << "shifting all elements to the right: " << endl;
	shift(numbers, CAP);


	system("pause");
	return 0;
}

[integralfx]

values[i] = values[i + 1];
What happens when i == size - 1?

Also, I'd recommend that you move

int temp;
temp = values[size - 1];
values[0] = temp;

outside the for-loop so you don't unnecessarily perform operations on it.

Where is your main()?


Line 18: infinite recursion?

[Chamat]

when I try i < size - 1, the array prints 9 values instead of 10.

and I edited the code because I messed up the copy paste.

[integralfx]

when I try i < size - 1, the array prints 9 values instead of 10.

and I edited the code because I messed up the copy paste.

Print the array in another function. Don't try to do two things in a single function.

[Chamat]

Print the array in another function. Don't try to do two things in a single function.

I don't think it really matters where I print it.

I chose to print it there because I'm printing multiple functions using the array.

In any case I'm asking about fixing the shift function.

[Handy Andy]

Hello Chamat,

Untested, but the more I look at the shift function the more I come to the conclusion that it actually shift to the left not the right. This is what I did to fix the problem:

void printArray(int values[], const int size)
{
	for (size_t i = 0; i < size; i++)
	{
		std::cout << std::setw(4) << values[i];
	}
	std::cout << std::endl;
}

void shift(int values[], const int size)
{
	int tempArray[10]{ values[size - 1] }; // Sets tempArray[0] to the last eleent of values. As a bonus everything else is set to zero.

	for (int i = 1; i < size; i++)  // Starts at 1 because 0 is taken care of.
	{
		tempArray[i] = values[i - 1];
	}
	values = tempArray;

	printArray(tempArray, size);  // Printed here because numbers in main did not change.
}

It works except "numbers" in main does not get changed. Have not figured out that part yet because I could not pass the array by reference. That is why I printed the "tempArray" from within the "shift" function. Maybe someone else will have an answer for passing the array.

Hope that helps,

Andy

[lastchance]

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <iomanip>
using namespace std;

template <class T> void shift( T values[], int size)
{
   T temp;
   temp = values[size - 1];
   for ( int i = size - 1; i > 0; i-- ) values[i] = values[i-1];
   values[0] = temp;
}


template <class T> void print( T values[], int size, int width )
{
   for ( int i = 0; i < size; i++ ) cout << setw( width ) << values[i];
   cout << endl;
}


int main()
{
   const int CAP = 10;
   cout << "Random " << CAP << " index array" << endl;
   int numbers[CAP];
   srand(time(0));
    
   for ( int i = 0; i < CAP; i++ ) numbers[i] = rand() % 100 + 1;
   cout << "Initial numbers: \n";   print<int>( numbers, CAP, 4 );

   shift<int>( numbers, CAP );
   cout << "Shifted numbers: \n";   print<int>( numbers, CAP, 4 );

   system("pause");
   return 0;
}