Question

-Write a function is_perfect, which accepts a single integer as input. If the input is not positive, the function should return a string "Invalid input." If the input is positive, the function should return True if the input is a perfect number and False otherwise.

Answer 1

Answer:

// here is code in C++.

#include <bits/stdc++.h>

using namespace std;

// function

string is_perfect(int n)

{

   // string variables

   string str;

   // if number is negative

   if (n < 0)

   {

        str="invalid input.";

   }

   // if number is positive

   else

   {

      int a=sqrt(n);

      // if number is perfect square

      if((a*a)==n)

      {

          str="True";

      }

      // if number is not perfect square

      else

      {

          str="False";

      }

   }

   // return the string

     return str;

}

// main function

int main()

{

   // variables

int n;

cout<<"enter the number:";

// read the value of n

cin>>n;

// call the function

string value=is_perfect(n);

// print the result

cout<<value<<endl;

return 0;

}

Explanation:

Read a number from user and assign it to variable "n".Then call the function is_perfect() with parameter n.First check whether number is negative or not. If number is negative then return a string "invalid input".If number is positive and perfect square then return a string "True" else return a string "False".

Output:

enter the number:-3

invalid input.

enter the number:5

False

enter the number:16

True