Answer:
// program in Python to check perfect number
#function to find number is perfect or not
def is_Perfect_Number(n):
#total variable
tot = 1
i = 2
#sum of all divisor of number
while i*i<=n:
if n%i==0:
tot = tot + i + n/i
if tot == n and n != 1:
return 1
i = i+1
return 0
#read until user enter a perfect number
while True:
#read integer
num = int(input("Input an integer: "))
#call the function
if(is_Perfect_Number(num)):
print(num,"is perfect number")
#if perfect number break
break
else:
print(num,"is not a perfect number")
#ask again
print("try again.")
Explanation:
Read number from user and then call the function is_Perfect_Number() with parameter "num".This will find the sum of all divisor of number.If sum is equal to number then it will return 1 else return 0.If the number is not perfect then it will again ask to enter a number until user enter a perfect number.
Output:
Input an integer: 24
24 is not a perfect number
try again.
Input an integer: 28
28 is perfect number
Answer : The securtiy of the password can be maitained by the shadow files such as:-
- max is for the days that represent that the same password can be used without the need for changing it
- min is for the days that represent waiting days before the changing of password after he/she gets a new password
- warn are the days that come with Waring sign that the password is going to expire soon.
For a certain period of time , the user can access the log in when the password has expired . If that period is timed out then there will be no log in option and the account gets disabled.
Answer:
Around seven billion people
