1 files changed, 48 insertions, 0 deletions

diff --git a/3/4.c b/3/4.c
new file mode 100644
index 0000000..1ec8d15
--- /dev/null
+++ b/3/4.c
@@ -0,0 +1,48 @@
+#include <ctype.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+#define MAXLEN 50
+
+void itoa(int n, char s[]);
+void reverse(char s[]);
+
+int main(int argc, char *argv[]) {
+  char s[MAXLEN];
+
+  itoa(INT_MIN, s);
+  printf("Largest negative number on machine: %d\n", INT_MIN);
+  printf("Largest negative number after itoa: %s\n", s);
+
+  return 0;
+}
+
+void itoa(int n, char s[]) {
+  int i, sign;
+
+  i = 0;
+  
+  if ((sign = n) < 0)
+    n = -n;
+
+  do {
+    s[i++] = n % 10 + '0';
+  } while ((n /= 10) > 0);
+
+  if (sign < 0)
+    s[i++] = '-';
+  s[i] = 0;
+  
+  reverse(s);
+}
+
+void reverse(char s[]) {
+  int c, i, j;
+
+  for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
+    c = s[i];
+    s[i] = s[j];
+    s[j] = c;
+  }
+}
\ No newline at end of file