# C Program to check if the given two numbers are friendly pair or not

## Program to Check if the given two numbers are friendly pair or not.

Here, in this section we will discuss the C program to check whether two numbers are friendly pair or not. Friendly pair or Amicable numbers are two different numbers related in a way such that the sum of the proper divisors of each is equal to the other number. A proper divisor is a positive factor of that number other than the number itself ,for Example proper divisors of 6 are 1, 2, and 3.

## Working:-

Step 1. Start

Step 2. Input the numbers 1 and 2.

Step 3. Initialize two variables, sum1 and sum 2 with zero.

Step 4. Assign sum 1 with the sum of all the divisors of number 1.

Step 5.  Assign sum 2 with the sum of all the divisors of number 2.

Step 6. If (sum 1==number1) and (sum 2==number 2), then print, “Friendly Numbers”

Step 7. Else print “Not Friendly Numbers”.

Step 8. Stop

## C Programto test a friendly pair

`#include<stdio.h> int main(){    //1 Create two variables to use in first and second numbers      int i;      int f_Num,s_Num;    //2 two more variables created to store the sum of the divisors       int f_DivisorSum = 0;      int s_DivisorSum = 0;    //3 Asking user to enter the two numbers       printf("Enter two numbers to check if Amicable or not : ");       scanf("%d %d",&f_Num,&s_Num);    //4 Using one variable for loop and second to check for each number      for(int i=1;i<f_Num;i++)      {           //5 Condition check           if(f_Num % i == 0)               f_DivisorSum = f_DivisorSum + i;      }      //6 Calculating the sum of all divisors     for(int i=1;i<s_Num;i++)     {          if(s_Num % i == 0)              s_DivisorSum = s_DivisorSum + i;     }     //7 Check condition for friendly numbers     if((f_Num == s_DivisorSum) && (s_Num == f_DivisorSum))printf("%d and %d are Amicable numbers\n",f_Num,s_Num);     else     {          printf("%d and %d are not Amicable numbers\n",f_Num,s_Num);     }    return 0;}`

## Output

```Enter two numbers to check if Amicable or not : 12 13
12 and 13 are not Amicable numbers
```

### One comment on “C Program to check if the given two numbers are friendly pair or not”

• Pavendhan

Above code is incomplete.

#include
int main()
{
//1 Create two variables to use in first and second numbers
int i;
int f_Num,s_Num;
//2 two more variables created to store the sum of the divisors
int f_DivisorSum = 0;
int s_DivisorSum = 0;

//3 Asking user to enter the two numbers
printf(“Enter two numbers to check if Amicable or not : “);
scanf(“%d %d”,&f_Num,&s_Num);

//4 Using one variable for loop and second to check for each number
for(int i=1;i<f_Num;i++)
{
//5 Condition check
if(f_Num % i == 0)
f_DivisorSum = f_DivisorSum + i;
}
//6 Calculating the sum of all divisors
for(int i=1;i<s_Num;i++)
{
if(s_Num % i == 0)
s_DivisorSum = s_DivisorSum + i;
}
int fai=(f_DivisorSum/f_Num);
int sai=(s_DivisorSum/s_Num);
//7 Check condition for friendly numbers
if(fai==sai)
{
printf("%d and %d are Amicable numbers\n",f_Num,s_Num);
}
else
{
printf("%d and %d are not Amicable numbers\n",f_Num,s_Num);
}
return 0;
}