1 files changed, 63 insertions, 0 deletions
diff --git a/3/5.c b/3/5.c
new file mode 100644
index 0000000..b5c833e
--- /dev/null
+++ b/3/5.c
@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAXLEN 100
+
+/* converts n to string in base b representation */
+void itob(int n, char s[], int b);
+
+int main(int argc, char *argv[]) {
+  int n, b, c, i;
+  char s[MAXLEN];
+
+  printf("Number: ");
+  for (i = 0; i < MAXLEN - 1 && (c = getchar()) != '\n' && c != EOF; i++)
+    s[i] = c;
+  s[i] = 0;
+  n = atoi(s);
+
+  printf("Base: ");
+  for (i = 0; i < MAXLEN - 1 && (c = getchar()) != '\n' && c != EOF; i++)
+    s[i] = c;
+  s[i] = 0;
+  b = atoi(s);
+
+  itob(n, s, b);
+  printf("%d in base %d: %s\n", n, b, s);
+
+  return 0;
+}
+
+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;
+  }
+}
+
+void itob(int n, char s[], int b) {
+  int i, sign;
+
+  i = 0;
+  sign = n < 0;
+
+  if (n >= 0) {
+    do {
+      s[i++] = (n % b) + '0';
+    } while ((n /= b) > 0);
+  } else {
+    do {
+      s[i++] = -(n % b) + '0';
+    } while ((n /= b) <= -1);
+  }
+
+  if (sign)
+    s[i++] = '-';
+  s[i] = 0;
+
+  reverse(s);
+}