euler55

#include <stdio.h>

typedef unsigned long long int BigNumber;

BigNumber reverse(BigNumber number)
{
    BigNumber rem = 0;
    while (number > 0) {
        rem = (rem * 10) + (number % 10);
        number = number / 10;
    }
    return rem;
}

bool isPalindrome(BigNumber num) {
    return (num == reverse(num));
}

bool isLychrelNum(int num, const int iterCount = 50) {
    BigNumber temp = num;
    BigNumber rev;
    for (int i = 0; i < iterCount; i++) {
        rev = reverse(temp);
        if (isPalindrome(rev + temp))
            return false;
        temp = temp + rev;
    }
    return true;

}

int main(int argc, char** argv) {
    const int maxnum = 10000;
    int counter = 0;

    for (int i = 1; i <= maxnum; i++) {
        if (isLychrelNum(i))
            counter++;
    }

    printf("There are %d Lychrel numbers from 1 to %d.\n", counter, maxnum);
    return 0;
}