-->




FIND THE PERFECT NUMBER IN C++

22 comments
What is a perfect number?
"Perfect number is a positive number which sum of all positive divisors excluding that number.
For example 6 is Perfect Number since divisor of 6 are 1, 2 and 3. Sum of its divisor is
1 + 2+ 3 =6
and  28 is also a Perfect Number
 since 1+ 2 + 4 + 7 + 14= 28
Other perfect numbers: 496, 8128




  1. #include<iostream.h>
  2. #include<conio.h>
  3. void main()                 //Start of main
  4. {
  5.   clrscr();
  6.    int i=1, u=1, sum=0;
  7.    while(i<=500)
  8.  {                                  // start of first loop.

  9.    while(u<=500)
  10.    {                               //start of second loop.
  11.      if(u<i)
  12.      {
  13.       if(i%u==0 )
  14.       sum=sum+u;
  15.      }                          //End of if statement
  16.     
  17.      u++;
  18.    }                           //End of second loop

  19.    if(sum==i)
  20.    {
  21.     cout<<i<<" is a perfect number."<<"\n";
  22.    }

  23.    i++;
  24.    u=1;  sum=0;
  25.  }                             //End of First loop
  26.    getch();
  27.  }                            //End of main

Sample output

is a perfect number.
28 is a perfect number.
496 is a perfect number.

Note:
If you want to calculate perfect number within your desire limit simply take a variable and replaced 500 with it.

22 comments:

  1. In APL: isPerfect←{⍵=+/(⍳⍵-1){(0=⍺|⍵)/⍺}⍵}

    isPerfect 28
    1

    ReplyDelete
  2. Also...
    {⍵ if isPerfect ¨⍵}⍳500
    6 28 496

    ReplyDelete
  3. very nice.was a great support for me!!!!!

    ReplyDelete
  4. AM NEW DUDE. SO WHERE DO I START?

    ReplyDelete
    Replies
    1. You Need To Understand The Basics Of C++ Programming.
      Try To Practice As Much As You Can.
      Practice is Very Important For Your Solid Base to Learn Programming.. Good Luck

      Delete
  5. Fahad bhai: i am new where do i start ?

    ReplyDelete
    Replies
    1. Waqas Bhai.
      You Need To Understand The Basics Of C++ Programming.
      Try To Practice As Much As You Can.
      Practice is Very Important For Your Solid Base to Learn Programming.. Good Luck

      Delete
  6. #include

    using namespace std;



    int main()
    {
    int num,perfect;
    int per=0;
    cout<<"enter number \n";
    cin>>num;
    int newnum=num;
    for(int i=1;i<=num;i++){
    if(num%i == 0){
    perfect=i;
    cout<<perfect<<endl;
    per=per+perfect;
    }
    }

    if(newnum == per/2){
    cout<<"perfect";
    }else{
    cout<<"not perfect";
    }


    }

    ReplyDelete
  7. This comment has been removed by the author.

    ReplyDelete
  8. A.o.A Fahad ..
    Your website is really really helping. I am a beginner in C++.I have made a more simplest logic for perfect numbers and it works.


    #include
    #include
    using namespace std;
    int main()
    {
    int a,b,c;
    c=0;
    cout<<"Plz enter a number :";
    cin>>b;
    for(a=1;a<b;a++)
    {
    if(b%a==0)

    c=c+a;

    }
    if(c==b)
    cout<<"Yes it is a Perfect number";
    else
    cout<<"No it is not a perfect number";

    getch();

    }

    ReplyDelete
  9. This comment has been removed by the author.

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
  10. How To Use C++ In Windows7? Becoz in my system windows7 there are not operating c Language & C++ Plz Help...

    ReplyDelete
  11. All the programs are really helpful... but i need more guidance bcuz every time i try to write program, i literally get confused! PLZ HELP ME GET OUT OF IT BCUZ I AM DOING SOFTWARE ENGG! I REALLY NEED HELP

    ReplyDelete