Recursion
Factorial #include <stdio.h> unsigned long fact( int ); void main() { int a; printf ( "\nenter value of n " ); scanf ( "%d" ,&a); printf ( "\n%d" ,fact(a)); /*b=sum(a); printf("\n%d",b);*/ } unsigned long fact( int a) { if (a== 1 ) return 1 ; return (a*fact(a- 1 )); } Fibonacci #include <stdio.h> void main() { int a= 0 ,i= 0 ; //b=1,n,i=2,sum=0; printf ( "\nenter length" ); scanf ( "%d" ,&a); for (i= 1 ;i<=a;i++) printf ( "\n%d" ,fib(i)); } int fib( int a) { if (a== 1 ) return 0 ; else if (a== 2 ) return 1 ; return (fib(a- 1 )+fib(a- 2 )); } GCD //greatest common devider #include <stdio.h> void main() { int a,b; printf ( "\nenter values " ); scanf ( "%d%d" ,&a,&b); printf ( "%d" ,gcd(a...