chapter7

DeitelC/Chapter6/palindromes.c

@@ -0,0 +1,41 @@
+ #include <stdio.h>
+ #include <string.h>
+
+ int palindromes(const char *c);
+ int testPal(const char *c, int start, int end);
+
+ int palindromes(const char *c) {
+	 int length = 0;
+	 while (c[length] != '\0') {
+		 length++;
+	 }
+
+	 return testPal(c, 0, length - 1);
+ }
+
+ int testPal(const char *c, int start, int end) {
+	 int test = 1;
+	 
+	 if(start >= end) {
+		 return test;
+	 }
+
+	 if(c[start] != c[end]) {
+		 return !test;
+	 }
+
+	 return testPal(c, ++start, --end);
+
+	 return test;
+ }
+
+ int main (void) {
+	 char str1[] = "radar";
+	 char str2[] = "A man, a plan, a canal: Panama";
+	 char str3[] = "hello";
+
+		 printf("%s is %s a palindrome\n", str1, palindromes(str1) ? "" : "not");
+		 printf("%s is %s a palindrome\n", str2, palindromes(str2) ? "" : "not");
+		 printf("%s is %s a palindrome\n", str3, palindromes(str3) ? "" : "not");
+	 return 0;
+ }