add problem 9 add test function

Author: supercoderhawk

C/1-50/9-Palindrome-Number.c

@@ -0,0 +1,39 @@
+/*
+ * Determine whether an integer is a palindrome. Do this without extra space.
+ * Created by supercoderhawk on 2017/7/24.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include "../main.h"
+
+bool isPalindrome(int x) {
+    if(x == 0)
+        return true;
+    if(x<0)
+        return false;
+    int length = 0, num = x;
+    int *digits = (int*)malloc(sizeof(int)*10);
+
+    while(num!=0)
+    {
+        digits[length++] = num%10;
+        num/=10;
+    }
+    if(length == 1)
+        return true;
+
+    for(int i = 0; i < length/2;i++)
+    {
+        if(digits[i] != digits[length-1-i])
+            return false;
+    }
+    return true;
+}
+
+void testIsPalindrome()
+{
+    printf("%d\n", isPalindrome(54245));
+    printf("%d\n", isPalindrome(54246));
+    printf("%d\n", isPalindrome(112211));
+    printf("%d\n", isPalindrome(1000000001));
+}