Python program to check whether two numbers are Friendly Pair

September 28, 2022

Check Whether or Not the Two Numbers  are Friendly Pairs in Python

Given two integer numbers as the input, the objective is to check whether or not the two numbers are Friendly pairs of each other. Therefore, we’ll write a Program to Check Whether or Not the Two Numbers are Friendly Pairs in Python.

Example
Input : 6 28
Output : Yes, they are a friendly pair
friendly pair or not in python

Check Whether or Not the Two Numbers are Friendly Pairs in Python Language

Given two integer inputs as the numbers, the objective is to check whether the (divisors)/number ratio for the both the numbers are same or not. To do so we’ll run a loop to first find all the factors the the two numbers and then we’ll get the ratio using the above mentioned formula. We check whether the ratios are matching or not. Here are some of the methods we’ll use to Check Whether or Not the Two Numbers are Friendly Pairs in Python Language,

  • Method 1: Using the Range until Number.
  • Method 2: Using the Range until Sqrt( Number )

We’ll discuss the above mentioned methods in detail in the upcoming sections. Do check the blue box mentioned below for better understanding. Check out the python page to Find all the Factors of a Number for better understanding.

Method 1: Using the Range until Number

In this method we’ll check for factors in the range of 2 to the number itself. We’ll define a function that returns all the factors of a given number. Then we’ll sum them up and divide with the number itself to get the required ratio. In the end we’ll do the same for both the numbers and match their ratio.

Python Code

Run 
def printDivisors(n, factors) :
    i = 1
    while i <= n :
        if (n % i==0) :
            factors.append(i)
        i = i + 1
    return sum(factors) - n

if __name__ == "__main__": 
  number1, number2 = 6, 28
  if int(printDivisors(number1, [])/number1) == int(printDivisors(number2, [])/number2):
    print("Friendly pair")
  else:
    print("Not a Friendly Pair")

Output

Friendly pair

Method 2: Using the Range until Sqrt( Number )

In this method we’ll use a loop within a function to find all the factors of the given number input. We’ll run the loop from 2 to the square root of the number. Once we get all the factors except the number itself, we’ll sum them all up and divide it with the same number. We’ll do the same for both numbers and match the ratio.

Python Code

Run 
def printDivisors(n, factors) :
     
    # Note that this loop runs till square root
    i = 1
    while i <= pow(n,0.5):
         
        if (n % i == 0) :
             
            # If divisors are equal, print only one
            if (n / i == i) :
                factors.append(i)
            else :
                # Otherwise print both
                factors.append(i)
                factors.append(int(n/i))
        i = i + 1
    return sum(factors) - n

if __name__ == "__main__": 
  number1, number2 = 6, 28
  if int(printDivisors(number1, [])/number1) == int(printDivisors(number2, [])/number2):
    print("Friendly pair")
  else:
    print("Not a Friendly Pair")

Output

Friendly Pair

Strong number

Perfect number

Harshad number

Automorphic number

Abundant number

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26 comments on “Python program to check whether two numbers are Friendly Pair”


  • Thanushree N

    def friendly(n):
    s=0
    for i in range(1,int(n/2)+1):
    if n%i==0:
    s=s+i
    return s
    a,b=input().split()
    a,b=int(a),int(b)
    a1=friendly(a)
    a2=friendly(b)
    if a1//a==a2//b:
    print(“f”)
    else:
    print(“n”)


      • nallavalli

        # Python program to check whether two numbers are Friendly Pair.
        #Example
        #Input : 6 28
        #Output : Yes, they are a friendly pair
        #Explanation : The factors of 6 and 28 except the numbers themselves are 1, 2, 3 and 1, 2, 4, 7, 14 respectively.
        #Now the sum of factors of both the numbers are 6 and 28 respectively.
        #When we divide the sums with the numbers we get 1 and 1 respectively.
        #As the ratio of both the number match, they are considered as a friendly pair.
        n1=int(input())
        n2=int(input())
        sum=0
        sum1=0
        for i in range(1,n1):
        if n1%i==0:
        sum=sum+i
        for j in range(1,n2):
        if n2%j==0:
        sum1=sum1+j
        if sum//n1 == sum1//n2:
        print(“Friendly pair”)
        else:
        print(“Not Friendly pair”)


  • Abhishek

    # Try This
    def factors_sum(n):
    s=0
    for i in range(1,n//2+1):
    if n%i==0:
    s+=i
    return s

    a,b=input().split()
    a,b=int(a),int(b)
    sum_a=factors_sum(a)
    sum_b=factors_sum(b)
    print(“\nFriendly Pair” if a/sum_a==b/sum_b else “Not a Frendly Pair”)


  • vamsi

    a=int(input(“”))
    b=int(input(“”))
    s=0
    d=0
    for i in range(1,a):
    if(a%i==0):
    s=s+i
    for i in range(1,b):
    if(b%i==0):
    d=d+i
    if(a/s==b/d):
    print(“yes”)
    else:
    print(“no”)


  • yaswanth

    num1=6
    num2=28
    sum1=0
    sum2=0
    for i in range(1,num1):
    if(num1%i==0):
    sum1=sum1+i
    for i in range(1,num2):
    if(num2%i==0):
    sum2=sum2+i
    if (sum1==num1 and sum2==num2):
    print(” friendly pair”)
    else:
    print(“not friendly pair”)


  • Sangram

    N1, N2 = 6, 28
    ls1, ls2 = [i for i in range(1, N1) if N1 % i == 0], [i for i in range(1, N2) if N2 % i == 0]
    print(“FriendlyPair” if sum(ls1)/N1==1 and sum(ls2)/N2==1 else “False”)


  • D

    n,m=int(input()),int(input())
    s,c=0,0
    for i in range(1,n):
    if n%i==0:
    s+=i
    for j in range(1,m):
    if m%j==0:
    c+=j

    if (s/n)==(c/m):
    print(“friendly pair”)
    else:
    print(“not friendly pair”)


  • Madipadige

    a,b=[int(x) for x in input().split()]
    c,d= sum([i for i in range(1,a) if a%i==0]),sum([i for i in range(1,b) if b%i==0])
    if(c//a==1 and d//b==1):
    print(“friendly pair”)
    else:
    print(“not a friendly pair”)


  • as138842

    n , m = map(int,input(“Give input = “).split())

    def allfactors(n):
    factors = [1]
    for i in range(2, (n // 4) + 2):
    if n % i == 0 and i not in factors:
    factors.append(i)
    if (n // i) not in factors:
    factors.append(n // i)
    return factors
    def isFriendlyPair(num1,num2):
    sum1 = sum(allfactors(num1))
    sum2 = sum(allfactors(num2))
    if sum1/num1 == sum2/num2:
    return “Yes this number is a Friendly Pair”
    else:
    return “No it is not a Friendly Pair”
    print(isFriendlyPair(n,m))


  • cherith

    n1=int(input())
    n2=int(input(” “))
    sum1=0
    sum2=0
    for i in range(1,n1):
    if n1%i==0:
    sum1+=i
    print(sum1)
    for j in range(1,n2):
    if n2%j==0:
    sum2+=j
    print(sum2)
    a=sum1/n1
    b=sum2/n2
    print(a,b)
    if a==b:
    print(“friendly pairs”)
    else:
    print(“no”)


  • AMIT

    num1=int(input(“Enter the number: “))
    num2=int(input(“Enter the number : “))
    def sumfactor(n):
    sum=1
    for i in range(2,n):
    if n%i== 0:
    sum = sum + i
    return sum

    a=sumfactor(num1)
    b=sumfactor(num2)

    if a/num1 == b/num2 :
    print(“It is the friendly pair”)
    else:
    print(“It is not the friendly pair”)


  • Ashish

    n=int(input(“Enter first Number “))
    m=int(input(“Enter Second Number “))
    a=0
    b=0
    for i in range(1,n+1):
    if n%i==0:
    a=a+i
    else:
    pass
    for i in range(1,m+1):
    if m%i==0:
    b=b+i
    else:
    pass
    print(a,b)
    if a/n==b/m:
    print(“Friendly Number”)
    else:
    print(“Not Friendly Number”)

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