feat(solutions): add print-pyramid/rust/function

challenges/print-pyramid/solutions/rust/function/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "rust_application"
+version = "1.0.0"

challenges/print-pyramid/solutions/rust/function/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "rust_application"
+version = "1.0.0"
+edition = "2021"
+
+[dependencies]

challenges/print-pyramid/solutions/rust/function/README.md

@@ -0,0 +1,3 @@
+# print-pyramid/rust/function
+
+Created by [@theoludwig](https://github.com/theoludwig) on 2 August 2023.

challenges/print-pyramid/solutions/rust/function/src/main.rs

@@ -0,0 +1,36 @@
+use std::io;
+
+fn main() {
+    let mut pyramid_type = String::new();
+    io::stdin()
+        .read_line(&mut pyramid_type)
+        .expect("Failed to read `stdin` line.");
+    pyramid_type = pyramid_type.trim().to_string();
+    let mut height = String::new();
+    io::stdin()
+        .read_line(&mut height)
+        .expect("Failed to read `stdin` line.");
+    let height: usize = height
+        .trim()
+        .parse()
+        .expect("Failed to convert `height` as an `usize`.");
+
+    let mut step = if pyramid_type == "normal" { 1 } else { height };
+    while (pyramid_type == "normal" && step <= height) || (pyramid_type == "reverse" && step != 0) {
+        let number_of_stars = (step * 2) - 1;
+        let total_number_of_locations = (height * 2) - 1;
+        let total_number_of_spaces = total_number_of_locations - number_of_stars;
+        let number_of_spaces_on_each_side = total_number_of_spaces / 2;
+        println!(
+            "{}{}{}",
+            " ".repeat(number_of_spaces_on_each_side),
+            "*".repeat(number_of_stars),
+            " ".repeat(number_of_spaces_on_each_side)
+        );
+        if pyramid_type == "normal" {
+            step = step + 1;
+        } else {
+            step = step - 1;
+        }
+    }
+}