Euler Problem 4: Largest palindrome product : C Programming Solution

Problem 4:

A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.

Find the largest palindrome made from the product of two 3-digit numbers.

Solution Approach:

Brute force method:

Create a function that checks a number for being a palindrome.

keep multiplying the numbers from 999 X 999 decretmenting one at a time.

Find the multiplication and get the highest product and print

Solution :

[code]

#include “stdio.h”

/* A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.
*
* Find the largest palindrome made from the product of two 3-digit numbers.
*/
int isPal(int num)
{
int temp=num;
int rev=0;
int dig=0;
while(temp>0)
{
dig=temp%10;
rev=rev*10+dig;
temp/=10;
}
if(rev==num)
return 1;
else
return 0;

}

int main ()
{

int prod=1;
int large=0;
int i,j;
for( i =999;i>=100;i–)
{
for(j=999;j>=100;j–)
{
prod=i*j;
if( isPal(prod) && prod>large)
{
large=prod;
}
}
}
printf(“largest palindrome prod is %d\n”,large);
return 0;
}

[/code]

Answer: 906609

Let me know your approach you happen to find a better way to solve this using C programming in the comment section below.

Happy coding !

Jeswin Augustine

I 'm a computer science graduate from Karunya University and I 'm a developer/designer. Born and brought up in India, I have worked with clients all around the globe.This blog serves as an informal and unorganized repository of things I ’ve worked on in my free time. It is mostly about programming for the web and sometimes for desktop application.