C program to reverse numbers in an array

general
,
1

Please add functions in the program given in the link below

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2

What do you want to do? I mean, what is the objective?

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3

Ops sorry i am also trying this function, but unable to get expected results. trying again.

4

hey hi,
I have just used pointers and function to enter and reverse the array as you asked, not print the reverse of the array :). the code was not copying properly so i just copied reverse function, entring and main function you can easily figure out on your own.

    void reverse(int a){
	int i;
	int* ptr1;
	int* ptr2,*temp;
	temp = &br[0];
	ptr2 = &ar[a-1];
	ptr1 = &ar[0];
		while(ptr2>=ptr1){
		*temp = *ptr1;
		*ptr1 = *ptr2;
		*ptr2 = *temp;
		ptr1++;
		ptr2--;
		temp++;
       }
5

Algorithm to reverse an array by swapping elements. Let inputArray is an array of length N, and leftIndex and rightIndex are integer variables.

  • Initialize leftIndex and rightIndex with index of first and last element of inputArray respectively.
  • leftIndex = 0; and rightIndex = N - 1;.
  • Swap inputArray[leftIndex] and inputArray[rightIndex].
  • Now, Increment leftIndex (leftIndex++) and decrement rightIndex(rightIndex–).
  • Repeat last two steps, until leftIndex < rightIndex.

Check this C program to reverse the elements of array.

6

include

main()
{
int a[10],n,i,l,r,t;
printf(“Enter n value”);
scanf("%d",&n);
printf(“Enter elements in the array:”);
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
l=0;
r=n-1;
for(i=0;i<n;i++)
{
if(l<r)
{
t=a[l];
a[l]=a[r];
a[r]=t;
}
l++;
r–;
}
for(i=0;i<n;i++)
{
printf("%d ",a[i]);
}
}

7

#include<stdio.h>
void main()
{
int a[20],i,n;
printf(“Enter the size of your array: \n”);
scanf("%d",&n);
printf(“Enter the array elements :\n”);
for(i=0;i<n;i++)
scanf("%d"a[i])
printf(“The array in reversed order is:\n”);
for(i=n;i>=0;i–)
printf(" %d ",a[i]);

}

8

you just traverse half array (n/2) and swap(a[i],a[n-i]){1-indexing} and it’s done for 0-indexing a[n-1-i] instead of a[n-i].useful(upvote)

9

Using functions and pointers write a c program to reverse the elements of an integer array,this is the question.But I was only used main function.please help.

10

Check this one. I have just edited your code. I have used another array to reverse the given array.

11

You can also reverse an array without any additional array by swapping the elements.

12

can you say why you used b[size-i-1]=a[i] *refer7*
why you used rev(arr,size)

13

in the program.Please explain that mathematically or logically.Thanks in advance.

14

for i=0 to size-1

b[size-i-1]=a[i]

This means,

b[size-1]=a[0], b[size-2]=a[1], b[size-3]=a[2], b[size-4]=a[3],… b[1]=a[size-2], b[0]=a[size-1]

Hare we are copying the elements of a[] to b[] in a reverse order. You should use a paper and dry run the code. I hope that will help you.

In the function rev() I have passed two parameters, the 1st one is the given array to reverse it and the second one is the size of the array.

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15

About 50viewers for this question,none other than you gived an answer.Thanks for your help.

16

No problem. You are always welcome :slight_smile:

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