Question

In C language using printf and scanf statements:

Write a program to display a histogram based on a number entered by the user. A histogram is a graphical representation of a number (in our case, using the asterisk character). On the same line after displaying the histogram, display the number. The entire program will repeat until the user enters zero or a negative number. Before the program ends, display "Bye...".

The program will ask the user to enter a non-zero positive number. Using a while loop, validate that the number is not greater than 40, and if so, re-ask for the number. Put the entire program into a sentinel-controlled loop so that the user can enter either zero (0) or a negative number to end the program.

Create constants for 1 (the minimum number for the histogram), and 40 (the maximum number for the histogram), and use these constants in the prompts, the validation condition and error message, and the sentinel-controlled loop and the histogram loop.

Hints:

• Validation messages are indented 3 spaces
• You can use either a pre-test loop (with the initial prompt outside the loop, and the re-prompt at the end of the loop) or a post-test loop (with the prompt inside the loop, and a decision to print the histogram also inside to loop).
• Coded the histogram using a for loop (although any type of loop could be used)

Example Run:

(bold type is what is entered by the user)

Enter a non-zero positive number less than 40: 5
***** 5

Enter another non-zero positive number less than 40: 48
The number entered was greater than 40.
Please re-enter: 8
******** 8

Enter another non-zero positive number less than 40: -1

Bye...

The example run shows EXACTLY how your program input and output will look.

Answer 1

#include <stdio.h>

int main()
{
   int n = 1, i;
   while(n > 0){
      if(n > 40){
         printf("Please re-enter: ");
      }
      else{
         printf("Enter a non-zero positive number less than 40: ");
      }
      scanf("%d",&n);
      if(n >= 40){
         printf("The number entered was greater than 40.
");
      }
      else{
         for(i = 0;i<n;i++){
            printf("*");
         }
         if(n > 0)
            printf(" %d
",n);
      }
   }
   printf("Bye...");
   
   return 0;
}