upd

9. Palindrome Number/solution.c

@@ -0,0 +1,26 @@
+#include <stdlib.h>
+#include <stdbool.h>
+
+bool isPalindrome(int x) {
+    // negatives and numbers ending in 0 (except 0 itself) are not palindromes
+    if (x < 0 || (x % 10 == 0 && x != 0))
+        return false;
+
+    int reversedHalf = 0;
+
+    while (x > reversedHalf) {
+        reversedHalf = reversedHalf * 10 + x % 10;
+        x /= 10;
+    }
+
+    // for even digits: x == reversedHalf
+    // for odd digits:  x == reversedHalf / 10
+    return (x == reversedHalf) || (x == reversedHalf / 10);
+}
+
+
+int main(int argc, char *argv[])
+{
+  return EXIT_SUCCESS;
+}
+