add 3.6.c

1 files changed, 62 insertions, 0 deletions

diff --git a/3.6.c b/3.6.c
new file mode 100644
index 0000000..3ecdb50
--- /dev/null
+++ b/3.6.c
@@ -0,0 +1,62 @@
+#include <stdio.h>
+
+#define MAXLEN 25
+
+void reverse(char str[]);
+char* itoa(int n, char str[], int fieldwidth);
+
+int 
+main(void)
+{
+  int n = 214748;
+  char str[MAXLEN];
+
+  printf("%d\n", n);
+  printf("%s\n", itoa(n, str, 10));
+
+  return 0;
+}
+
+void
+reverse(char str[])
+{
+  int i, j;
+  char temp;
+
+  for (j = 0; str[j] != '\0'; j++)
+    ;
+
+  for (i = 0, --j; i < j; i++, j--) {
+    temp = str[i];
+    str[i] = str[j];
+    str[j] = temp;
+  }
+}
+
+char*
+itoa(int n, char str[], int fieldwidth)
+{
+  int sign, i;
+
+  /* to include the most -ve int */
+  n = ((sign = n) < 0) ? -(n+1) : n-1;
+
+  i = 0;
+  do {
+    str[i++] = n%10 + '0';
+  } while ((n /= 10) > 0);
+
+  if (sign <0)
+    str[i++] = '-';
+
+  while (i < fieldwidth)
+    str[i++] = ' ';
+
+  /* part of "to include the most -ve int" */
+  str[0] += 1;
+  str[i] = '\0';
+
+  reverse(str);
+
+  return str;
+}