C Exercises: Read n number of values in an array and display it in reverse order

C Array: Exercise-2 with Solution

Write a program in C to read n number of values in an array and display them in reverse order.

Visual Presentation:

Pseudo code:

Start
 Declare n, i as integer variables
 Declare nums as an integer array of size n
 Read n from the user
 Read values into the array nums from the user in a loop from i=0 to n-1
 Print "Array in reverse order: "
 For i=n-1 to 0 Step -1
   Print nums [i]
 End For
End

Sample Solution:

C Code:

#include <stdio.h>
// Main function
int main()
{
   int i, n, a[100];
   // Display a message to the user about the program's purpose
   printf("\n\nRead n number of values in an array and display it in reverse order:\n");
   printf("------------------------------------------------------------------------\n");
   // Prompt the user to input the number of elements to store in the array
   printf("Input the number of elements to store in the array :");
   scanf("%d", &n);
   // Prompt the user to input n elements into the array
   printf("Input %d number of elements in the array :\n", n);
   for (i = 0; i < n; i++)
   {
      printf("element - %d : ", i);
      scanf("%d", &a[i]);  // Read the input and store it in the array
   }
   // Display the values stored in the array
   printf("\nThe values stored in the array are : \n");
   for (i = 0; i < n; i++)
   {
       printf("% 5d", a[i]);  // Print each element in the array
   }
   // Display the values stored in the array in reverse order
   printf("\n\nThe values stored in the array in reverse are :\n");
   for (i = n - 1; i >= 0; i--)
   {
       printf("% 5d", a[i]);  // Print each element in reverse order
   }
   printf("\n\n");
   return 0;
}

Sample Output:

Read n number of values in an array and display it in reverse order:                                          
------------------------------------------------------------------------                                      
Input the number of elements to store in the array :3                                                         
Input 3 number of elements in the array :                                                                     
element - 0 : 2                                                                                               
element - 1 : 5                                                                                               
element - 2 : 7                                                                                               
                                                                                                              
The values store into the array are :                                                                         
    2    5    7                                                                                               
                                                                                                              
The values store into the array in reverse are :                                                              
    7    5    2

Explanation:

  printf("Input the number of elements to store in the array :");
   scanf("%d",&n);
   
   printf("Input %d number of elements in the array :\n",n);
   for(i=0;i<n;i++)
      {
	  printf("element - %d : ",i);
	  scanf("%d",&a[i]);
	  }
      
   printf("\nThe values store into the array are : \n");
   for(i=0;i<n;i++)
     {
	   printf("% 5d",a[i]);
	 }
 
   printf("\n\nThe values store into the array in reverse are :\n");
   for(i=n-1;i>=0;i--)
      {
	   printf("% 5d",a[i]);
	  }
   printf("\n\n");

In the above code -

• The first printf statement prompts the user to input the number of elements they want to store in the array and stores it in the variable n using scanf.
• The second printf statement asks the user to input n number of elements into the array using a for loop, and stores each input in the corresponding index of the array a[i].
• The third printf statement then prints out the contents of the array in order using another for loop.
• The fourth printf statement then prints out the contents of the array in reverse order using yet another for loop, which iterates over the elements of a starting from the last element and printing each element out in reverse order.

Flowchart:

C Programming Code Editor:

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