feat(math): add palindrome number checker in C++ without non-standard headers

Author: siddharthhkk

math/palindrome_number.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+// Function to check if a number is a palindrome
+bool is_palindrome_number(long long n) {
+    if (n < 0)
+        return false;  // Negative numbers are not palindromes
+    std::string s = std::to_string(n);
+    int i = 0, j = static_cast<int>(s.size()) - 1;
+    while (i < j) {
+        if (s[i] != s[j])
+            return false;
+        ++i;
+        --j;
+    }
+    return true;
+}
+
+#ifdef RUN_LOCAL
+int main() {
+    std::vector<long long> tests = {121, -121, 10, 12321, 0};
+    for (auto t : tests) {
+        std::cout << t << " -> " << (is_palindrome_number(t) ? "True" : "False")
+                  << "\n";
+    }
+    return 0;
+}
+#endif