Pass

**Very well done Oliver!**

Your solutions are correct. But don't forget the screenshots next time!

Tips:

_Your code_:
```rust
let mut rect: String = "".to_owned();
for i in 1..r as i32+1 {
for j in 1..k as i32+1 {
let rdist = (rmid - (i as f32 - rmid).abs()) as i32;
let kdist = (kmid - (j as f32 - kmid).abs()) as i32;
if rdist > 9 && kdist > 9 {
rect = rect + ".";
} else if rdist < kdist {
rect = rect + &rdist.to_string();
} else {
rect = rect + &kdist.to_string();
}
}
rect = rect + "\n"
}

println!("{}", rect);
```

_Optimised version_:
```rust
// Pre-allocate heap memory to prevent re-allocation upon push.
let mut rect: String = String::with_capacity(r*(k+1.0) as usize);

for i in 1..r as i32+1 {
for j in 1..k as i32+1 {
let rdist = (rmid - (i as f32 - rmid).abs()) as u32;
let kdist = (kmid - (j as f32 - kmid).abs()) as u32;

// Push characters instead of re-allocation upon re-assignment.
rect.push(
if rdist > 9 && kdist > 9 {
'.'
} else {
std::char::from_digit(
match rdist < kdist {
true => rdist,
false => kdist
}
).unwrap()
}
);
}
rect.push('\n');
}

println!("{}", rect);
```

_More optimised version_ (no additional heap memory allocation):
```rust
for i in 1..r as i32+1 {
for j in 1..k as i32+1 {
let rdist = (rmid - (i as f32 - rmid).abs()) as u32;
let kdist = (kmid - (j as f32 - kmid).abs()) as u32;

print!("{}",
if rdist > 9 && kdist > 9 {
'.'
} else {
std::char::from_digit(rdist.min(kdist)).unwrap()
}
);
}
println!();
}
```

No source file or test is named. Start by locating the Rust program that produces the shown rectangle output, then compare its current implementation with the snippets in the issue; completion is unclear because the issue provides feedback and optimization examples rather than a specific requested change.

Written by the indexing model from the issue text.