5 recusrion problems.py

# 1..TO FIND FACTORIAL OF A NUMBER USING RECURSION

deffactorial(n):
assertn>=0andint(n)==n , "the number must be positive integer only"
ifn==0orn==1:
return1
else:
returnn*factorial(n-1)

print(factorial(4))





# 2..TO PRINT FIBONACCI SERIES

deffibonacci(n):
assertn>=0andint(n)==n , "only positive integers"
ifn==0orn==1:
returnn
else:
returnfibonacci(n-1) +fibonacci(n-2)

print(fibonacci(8))





# 3.. TO FIND IF THE GIVEN STRING IS PALINDROME OR NOT

defisPalindrome(strng):
iflen(strng)==0:
returnTrue
ifstrng[0]==strng[-1]:
returnisPalindrome(strng[1:-1])

else:
returnFalse
print((isPalindrome('naman')))




# 4..TO FIND THE SUM OF ALL DIGITS IN THE GIVEN NUMBER

defsum(n):
assertn>=0andint(n)==n , "only positive integers"
ifn==0:
return0
else:
returnint(n%10) +sum(int(n//10))

print(sum(11))




# 5..TO FIND THE POWER OF A NUMBER

defpower(base,exp):
assertexp>=0andint(exp)==exp , "power can only be positive integers"
if(exp==0):
return1
if(exp==1):
returnbase
else:
returnbase*power(base,exp-1)

print(power(2,5))