C++ Program to Find Prime Factors of a Number

This article contains C++ program to find prime factors of a number. 

Steps:

(1) Read a positive integer x (using cin>>x) and initialize a variable i to 2.

(2) While x is divisible by i, print i and divide x by i.

(3) After step 2, increment i.

(4) Repeat step 3 and 4, till x>1.

C++ Program to Find Prime Factors of a Number

#include<iostream>

using namespace std;

int main()

{

    int x;

    cout<<"Enter a positive integer : ";

    cin>>x;

    cout<<endl<<"Prime factors of "<<x<<" are : "<<endl;

    for(int i=2;x>1;i++)

    {

        while(x%i==0)

        {

            cout<<i;

            x=x/i;

            cout<<"\t";

        }

    }

    return 0;

}

OUTPUT 1:

Enter a positive integer : 150

Prime factors of 150 are :

2       3       5       5

OUTPUT 2:

Enter a positive integer : 36

Prime factors of 36 are :

2       2       3       3

OUTPUT 3:

Enter a positive integer : 63

Prime factors of 63 are :

3       3       7