how to write a program that will take a number and check if it is divisible by 5 or not by not dividing the number by 5 (in python)

Question

在此代码中，我必须从用户处获取输入，并说输入是否可被5整除， 但无需使用 user % 5 == 0

Answer 1

Like this:

def f(x):
  return (x % 10) in (0, 5)

Or this:

def g(x):
  return x == x // 5 * 5

Or this slow one:

def h(x):
  if x < 0:
    x = -x
  while x >= 5:
    x -= 5
  return x == 0

Or this (also slow, but faster than h):

def i(x):
  return str(x)[-1] in '05'

Or this:

def j(x):
  return str(x << 1).endswith('0')

There are many more solutions.

Answer 2

t = int(input())
print(t/5==t//5)

or use

def f(x):
    return (t/5==t//5)

this will return true or false if the number is divisible by 5 or not.

PS. as pointed by @Pts this code is valid upto certain length of number(10^15) ,if number is too large floating point error come.

en.wikipedia.org/wiki/IEEE_754#Basic_and_interchange_formats indicates that 64-bit floats have 53-bit precisions, so numbers t whose absolute value is smaller than 2 ** 53 will work, others may fail

Answer 3

def main() :
 x = int(input("enter the number"))
 if x // 5 * 5 == x :
    print("yes")
 else:
    print("no")
main()

This worked

Answer 4

I naturally think of something like this:

def divisible(user, x):
    if (x > user or x <= 0):
        return False
    while (user > 0):
            user -= x
    return user == 0

Don't forget to check if x is negative and lower than user