Add menu progression

Author: Vianpyro

solution/solve_1.md

@@ -3,7 +3,7 @@ python3 -c "
 import sys
 sys.stdout.buffer.write(b'5\n')            # new ref
 sys.stdout.buffer.write(b'8\n')            # new admin
-sys.stdout.buffer.write(b'7\n0\n8\n')     # edit ref, idx=0, len=8
+sys.stdout.buffer.write(b'7\n0\n8\n')      # edit ref, idx=0, len=8
 import struct
 sys.stdout.buffer.write(struct.pack('<Q', 1))
 sys.stdout.buffer.write(b'\n')             # trailing newline (discard)

src/lib.rs

@@ -252,8 +252,14 @@ pub fn run<R: BufRead, W: Write>(r: &mut R, w: &mut W) -> io::Result<()> {
         writeln!(w, "5) New ref")?;
         writeln!(w, "6) Show ref")?;
         writeln!(w, "7) Edit ref")?;
-        writeln!(w, "8) New admin")?;
-        writeln!(w, "9) Show admin")?;
+
+        if !state.refs.is_empty() {
+            writeln!(w, "8) New admin")?;
+        }
+
+        if !state.admins.is_empty() {
+            writeln!(w, "9) Show admin")?;
+        }
 
         if state
             .admins