revise answer

Author: fsaadatmand

chapter04/4-13.c

@@ -1,73 +1,43 @@
 /*
  * Exercise 4-13. Write a recursive version of the function reverse(s), which
  * reverses the string s in place.
+ *
  * By Faisal Saadatmand
  */
 
 #include <stdio.h>
 #include <string.h>
-#include <limits.h>
+
+#define MAXLEN 1000
 
 /* functions */
 void reverse(char []);
-void itoa(int, char []);
 
 /* reverse function: reverse string s in place, recursive version */
 void reverse(char s[])
 {
-	int c, j;
-	static int i;
-
-	j = (strlen(s) - 1) - i;
-	if (j >= 0) {
-		c = s[i];
-		s[i++] = s[j];
-		s[j] = c;
+	int c;
+	static unsigned long i = 0, j = 0;
+	
+	if (j < strlen(s) - 1) {
+		++j;
 		reverse(s);
 	}
-}
-
-/* itoa: convert n to characters in s */
-void itoa(int n, char s[])
-{
-	int i, sign, lastDigit;
-
-	lastDigit = 0;
-	if (n == INT_MIN) {                   /* add check for size */
-		lastDigit = (n % 10 * -1) + '0';  /* extract save the last digit */
-		n -= 1;                           /* reduce n to fit INT_MAX */
+	if (i < j) {
+		c = s[i];
+		s[i++] = s[j];
+		s[j--] = c;
 	}
-
-	if ((sign = n) < 0)                   /* record sign */
-		n = -n;
-
-	i = 0;
-	do {                                  /* generate digits in reverse order */
-		s[i++] = n % 10 + '0';            /* get next digit */
-	} while ((n /= 10) > 0);
-
-	if (sign < 0)
-		s[i++] = '-';
-
-	if (lastDigit > 0)                    /* put back saved last digit */
-		s[0] = lastDigit;
-
-	s[i] = '\0';
-
-	reverse(s);
 }
 
 int main(void)
 {
-	int intValue;
-	char stringNumber[64];
-
-	printf("Enter integer to convert to a string: ");
-	scanf("%i", &intValue);
-
-	itoa(intValue, stringNumber);
+	char str[MAXLEN];
 
-	printf("%s\n", stringNumber);	
+	printf("Enter a string to reverse:\n");
+	scanf("%s", str);
+	reverse(str);
+	printf("%s\n", str);	
 
 	return 0;
 }