C Exercises: Hailstone Sequence of a given number upto 1

Last update on March 20 2025 12:37:47 (UTC/GMT +8 hours)

18. Hailstone Sequence Recursion Variants

Write a C program to find the Hailstone Sequence of a given number up to 1.

Sample Solution:

C Code:

#include <stdio.h>
 
// function to generate next number
   int getNextValue(int aNum)
   {
      int i = aNum;
      if (i % 2 == 0)
      {
         i = i/2;
      }
      else 
      { 
         i = 3 * i + 1;
      }
      return (i);// returning the value of next number to the called function
   }
// function to generate Hailstone number
   void getHailstone(int aNum)
   {
      int hlSe = aNum;  
      if (hlSe == 1)
      {
         printf("%i ", hlSe);
      }
      else
      {
         printf(" %i ", hlSe);
         getHailstone(getNextValue(hlSe));// calling the function itself recursively
      }
   }
// Function to count the length of the Hailstone sequence
   int countLength(int aNum)
   {
      int hlSe = aNum;  
      if(hlSe == 1)
      {
         return 1;
      }
      else
      {
         return 1+countLength(getNextValue(hlSe));// calling the function itself recursively
      }

   }

int main(int argu)
{
   int aNum;
    printf("\n\n Recursion : Hailstone Sequence of a given number upto 1 :\n");
	printf("--------------------------------------------------------------\n");  
   printf(" Input any number (positive) to start for Hailstone Sequence : ");
   scanf("%i", &aNum);

   printf("\n The hailstone sequence starting at %i is : \n", aNum);
   getHailstone(aNum);
   printf("\n\n");
   printf(" The length of the sequence is %i. \n\n", countLength(aNum));
      return 0;
}

Sample Output:

 Recursion : Hailstone Sequence of a given number upto 1 :                                                    
--------------------------------------------------------------                                                
 Input any number (positive) to start for Hailstone Sequence : 13                                             
                                                                                                              
 The hailstone sequence starting at 13 is :                                                                   
 13  40  20  10  5  16  8  4  2 1                                                                             
                                                                                                              
 The length of the sequence is 10

Flowchart:

For more Practice: Solve these Related Problems:

Write a C program to print the Hailstone sequence in reverse order using recursion.
Write a C program to count and display the number of steps in the Hailstone sequence recursively.
Write a C program to determine the maximum value reached in the Hailstone sequence using recursion.
Write a C program to check if the Hailstone sequence length is even or odd using recursion.

C Programming Code Editor:

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