Answer to Question #288933 in Python for rahul

Question

let x and y be the numbers obtained by reversing a and b, if both x and y are prime,then the answer is x+y and if exactly one of x and y is prime, then the answer is a+b.Otherwise ,the answer is a*b.Your task is write a function F(a,b) that takes integers a and b and returns a single digit integer value.Create seperate check_prime(n) and reverse(n) for checking a given number is prime and for reversing number.function must be generalized. Use only loops,if-else or if-elif-else and sting slicing,indexing as well simple inbuilt functions.

Answer 1

primes = [0 for i in range(10000000)]
def sieve(n):
    for i in range(2,int(n**1/2 +1)):
        if primes[i] ==0:
            j = i*i
            while j<=n:
                primes[j] = 1
                j +=i


def check(n):
    if primes[n] == 0:
        return True
    return False


def reverse(a,b):
    x,y = int(str(a)[::-1]),int(str(b)[::-1])
    return [x,y]
    
def F(a,b):
    x,y = reverse(a,b)
    if check(x) and check(y):
        return a+b
    else:
        return a*b


a = int(input())
b = int(input())


sieve(1000000)
print(F(a,b))