4 files changed, 142 insertions, 0 deletions
diff --git a/rust/theBook/chapter-3-variables-and-mutability/practice/convert-temp/Cargo.toml b/rust/theBook/chapter-3-variables-and-mutability/practice/convert-temp/Cargo.toml
new file mode 100644
index 0000000..391d95c
--- /dev/null
+++ b/rust/theBook/chapter-3-variables-and-mutability/practice/convert-temp/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "convert-temp"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/rust/theBook/chapter-3-variables-and-mutability/practice/convert-temp/src/main.rs b/rust/theBook/chapter-3-variables-and-mutability/practice/convert-temp/src/main.rs
new file mode 100644
index 0000000..971811e
--- /dev/null
+++ b/rust/theBook/chapter-3-variables-and-mutability/practice/convert-temp/src/main.rs
@@ -0,0 +1,59 @@
+use std::io;
+use std::process;
+
+fn read_input() -> i32 {
+    let mut input = String::new();
+
+    io::stdin()
+        .read_line(&mut input)
+        .expect("failed to read line");
+
+    let input = match input.trim().parse() {
+        Ok(input) => input,
+        Err(_) => {
+            println!("not a number!");
+            process::exit(1);
+        },
+    };
+    input
+}
+
+fn main() {
+    println!("Convert temperatures between Fahrenheit and Celsius");
+    println!("");
+
+    loop {
+        println!("Please choose converting method:");
+        println!("1) Fahrenheit to Celsius          2) Celsius to Fahrenheit");
+        println!("3) exit");
+
+        let choice = read_input();
+
+        if choice == 0 {
+            let _choice = read_input();
+        }   else if choice == 1 {
+            fah_to_cel();
+        }   else if choice == 2 {
+            cel_to_fah();
+        }   else if choice == 3 {
+            break
+        };
+    }
+    println!("Thinks for using");
+}
+
+fn fah_to_cel() {
+    println!("Please enter a Fahrenheit temperature");
+    let fah = read_input() as f32;
+
+    println!("the Celsius of {fah} is {}", (fah-32.0)/1.8);
+    println!("");
+}
+
+fn cel_to_fah() {
+    println!("Please enter a Celsius temperature");
+    let cel = read_input() as f32;
+
+    println!("The Fahrenteit of {cel} is {}", cel*1.8+32.0);
+    println!("");
+}
diff --git a/rust/theBook/chapter-3-variables-and-mutability/practice/fibonacci/Cargo.toml b/rust/theBook/chapter-3-variables-and-mutability/practice/fibonacci/Cargo.toml
new file mode 100644
index 0000000..9cd048e
--- /dev/null
+++ b/rust/theBook/chapter-3-variables-and-mutability/practice/fibonacci/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "fibonacci"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/rust/theBook/chapter-3-variables-and-mutability/practice/fibonacci/src/main.rs b/rust/theBook/chapter-3-variables-and-mutability/practice/fibonacci/src/main.rs
new file mode 100644
index 0000000..078f729
--- /dev/null
+++ b/rust/theBook/chapter-3-variables-and-mutability/practice/fibonacci/src/main.rs
@@ -0,0 +1,67 @@
+use std::io;
+use std::process;
+
+fn main() {
+    println!("Print nth Fibonacci number!");
+    println!("");
+
+    print_fibonacci();
+
+    println!("done!");
+}
+
+fn print_fibonacci() {
+    println!("Enter the n you want to print");
+
+    let fib = read_input();
+
+    println!("recursion_fibonacci:");
+    println!("{}", recursion_fibonacci(fib));
+    loop_fibonacci(fib);
+}
+
+fn loop_fibonacci(x: i32) {
+    let mut num1 = 0;
+    let mut num2 = 1;
+    let mut next: i32;
+
+    println!("loop_fibonacci:");
+
+    for _i in 0..x {
+        if _i <= 1 {
+            next = _i;
+        }   else {
+            next = num1 + num2;
+            num1 = num2;
+            num2 = next;
+        }
+        println!("{next}");
+    }
+}
+
+// Not recommend in rust
+fn recursion_fibonacci(x: i32) -> i32 {
+    if x <= 1 {
+        return x;
+    }   else {
+        recursion_fibonacci(x-1) + recursion_fibonacci(x-2)
+    }
+}
+
+fn read_input() -> i32 {
+    let mut inp = String::new();
+
+    io::stdin()
+        .read_line(&mut inp)
+        .expect("failed to read number");
+    
+    let inp: i32 = match inp.trim().parse() {
+        Ok(inp) => inp,
+        Err(_) => {
+            println!("converting error");
+            process::exit(1);
+        },
+    };
+
+    inp
+}