1 files changed, 65 insertions, 0 deletions
diff --git a/three/conv.c b/three/conv.c
new file mode 100644
index 0000000..d3e654e
--- /dev/null
+++ b/three/conv.c
@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <limits.h>
+
+void
+reverse(char s[])
+{
+	int i = 0;
+	while (s[i] != '\0') {
+		++i;
+	}
+	--i;
+	char c;
+	for (int j = 0; j < i / 2; ++j) {
+		c = s[i - j];
+		s[i - j] = s[j];
+		s[j] = c;
+	}
+}
+
+void
+itoa(int n, char s[])
+{
+	int i, sign;
+	if ((sign = n) < 0) {
+		n = -n - 1;
+	}
+	i = 0;
+	do {
+		s[i++] = n % 10 + '0';
+	} while ((n /= 10) > 0);
+	if (sign < 0) {
+		s[i++] = '-';
+	}
+	s[i] = '\0';
+	reverse(s);
+}
+
+void
+itob(int n, char s[], int b)
+{
+	int i, sign;
+	if ((sign = n) < 0) {
+		n = -n;
+	}
+	i = 0;
+	do {
+		s[i++] = (n % b <= 9) ? n % b + '0' : n % b - 10 + 'a';
+	} while ((n /= b) > 0);
+	if (sign < 0) {
+		s[i++] = '-';
+	}
+	s[i] = '\0';
+	reverse(s);
+}
+
+int
+main()
+{
+	char s[32];
+	itoa(INT_MIN, s);
+	printf("%s\n", s);
+	itob(380, s, 16);
+	printf("%s\n", s);
+	return 0;
+}