1 files changed, 34 insertions, 0 deletions
diff --git a/2.3.c b/2.3.c
new file mode 100644
index 0000000..21b0040
--- /dev/null
+++ b/2.3.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+
+int 
+main(void)
+{
+  char input;
+  int num;
+
+  num = 0;
+  
+  while ((input = getchar()) != EOF) {
+
+    if (input == '0') {
+      if ((input = getchar()) == 'x' || input == 'X')
+        continue;
+      else 
+        input = '0';
+    }
+
+    if (!((input >= '0' && input <= '9') || (input >= 'a' && input <= 'f') || (input >= 'A' && input <= 'F')))
+      continue;
+    else if (input >= '0' && input <= '9')
+      num = num * 16 + input - '0';
+    else if (input >= 'a' && input <= 'f')
+      num = num * 16 + 10 + input - 'a';
+    else if (input >= 'A' && input <= 'F')
+      num = num * 16 + 10 + input - 'A';
+
+  }
+
+  printf("\n%d\n", num);
+
+  return 0;
+}