Page 44 - DCAP201_FUNDAMENTALS_OF_DATA_STRUCTURES

Unit 3: Recursion

The output is given as below: Notes
Enter a sentence: margorp emosewa
awesome program
This program prints “Enter a sentence: “ then, Reverse() function is called. This function stores
the first letter entered by user and stores in variable c. If that variable is other than ‘\n’ [ enter
character] then, again Reverse()function is called. Don’t assume this Reverse() function and the
Reverse() function before is same although they both have same name. Also, the variables are
also different, i.e., c variable in both functions are also different. Then, the second character is
stored in variable c of second Reverse function. This process goes on until user enters ‘\n’. When,
user enters ‘\n’, the last function Reverse() function returns to second last Reverse() function and
prints the last character. Second last Reverse() function returns to the third last Reverse() function
and prints second last character. This process goes on and the final output will be the reversed
sentence.

Example 4: C Program to find HCF using recursion
This program takes two positive integers from user and calculates HCF or GCD using recursion.
Code to calculate H.C.F using recursion is given below:
/* Example to calculate GCD or HCF using recursive function. */
#include <stdio.h>
int hcf(int n1, int n2);
int main()
{
int n1, n2;
printf(“Enter two positive integers: “);
scanf(“%d%d”, &n1, &n2);
printf(“H.C.F of %d and %d = %d”, n1, n2, hcf(n1,n2));
return 0;
}
int hcf(int n1, int n2)
{
if (n2!=0)
return hcf(n2, n1%n2);
else
return n1;
}
The output is given as below:
Enter two positive integers: 366
60

H.C.F of 366 and 60 = 6

Task Illustrate the prime number program in c using recursion.

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