Why is my “Greatest Common Denominator” program not outputting the right information?

Question

This is my program to determine the "greatest common denominator of two numbers"

integer1 = int(input("Enter an integer:"))
integer2 = int(input("Enter an integer:"))

if integer1 > integer2:
    x = integer1
    while integer1%x and integer2%x !=0:
        x = x - 1

elif integer2 > integer1:
    x = integer2
    while integer1%x and integer2%x !=0:
        x = x - 1

print("the gcd of",integer1,"and",integer2,"is",x)

for example, when I input the values "25" and "50", my program will say the GCD is 50, which is incorrect.

Answer 1

x = min(integer1, integer2)
while integer1 % x or integer2 % x:
    x = x - 1

• avoid duplicating your code, just set x then apply your logic which doesn't change
• x can start at the minimum value rather than the maximum
• for x to be accepted it should satisfy both integer1 % x == 0 and integer2 % x == 0 , so the stop condition of your while should be integer1 % x != 0 or integer2 % x != 0 (and the !=0 are here redundant with int to bool conversion so you can skip them)
• in general a and b == 0 type of expression don't behave the way you probably think, the "correct" way is a == 0 and b == 0 .