Files
leetcode-cpp/9-palindrome-number.cpp

27 lines
763 B
C++

#include<iostream>
class PalindromeNumberSolution {
private:
void palindromer(unsigned long x, unsigned long *p, unsigned long d, unsigned long *max_d) {
if (x == 0) return;
if (d > *max_d) *max_d = d;
palindromer(x / 10, p, d * 10, max_d);
*p += x % 10 * (*max_d / d);
return;
}
public:
bool isPalindrome(int x) {
if (x < 0) return false;
if (x < 10) return true;
auto absX = (unsigned long)x;
std::cout << "absX = " << absX << std::endl;
unsigned long palindrome = 0;
unsigned long max_d = 0;
palindromer(absX, &palindrome, 1, &max_d);
//std::cout << "reverse(absX) = " << palindrome << std::endl;
return absX == palindrome;
}
};