Add assignment 2

src/assignments/assignment02.rs

@@ -1,3 +1,141 @@
 //! Assignment 2: Mastering common programming concepts (1/2).
+//!
+//! The primary goal of this assignment is to re-learn the common programming concepts in Rust, especially those in the Rust Book chapters 3 and 5.
+//! Please make sure you're comfortable with the concepts to proceed on to the next assignments.
+//!
+//! You should fill out the `todo!()` placeholders in such a way that `/scripts/grade-02.sh` works fine.
+//! See `assignment02_grade.rs` and `/scripts/grade-02.sh` for the test script.
 
-// TODO: use exercises in <https://doc.rust-lang.org/book/ch03-05-control-flow.html>
+use std::ops::Mul;
+
+const FARHENHEIT_OFFSET: f64 = 32.0;
+const FARHENHEIT_SCALE: f64 = 5.0 / 9.0;
+
+/// Converts Farenheit to Celcius temperature degree.
+pub(crate) fn farhenheit_to_celcius(degree: f64) -> f64 {
+    todo!()
+}
+
+/// Captializes English alphabets (leaving the other characters intact).
+pub(crate) fn capitalize(input: String) -> String {
+    todo!()
+}
+
+/// Returns the sume of the given array. (We assume the absence of integer overflow.)
+pub(crate) fn sum_array(input: &[u64]) -> u64 {
+    todo!()
+}
+
+/// Given a non-negative integer, say `n`, return the smallest integer of the form `3^m` that's greater than or equal to `n`.
+///
+/// For instance, up3(6) = 9, up3(9) = 9, up3(10) = 27. (We assume the absence of integer overflow.)
+pub(crate) fn up3(n: u64) -> u64 {
+    todo!()
+}
+
+/// Returns the greatest common divisor (GCD) of two non-negative integers. (We assume the absence of integer overflow.)
+pub(crate) fn gcd(lhs: u64, rhs: u64) -> u64 {
+    todo!()
+}
+
+/// Returns the array of nC0, nC1, nC2, ..., nCn, where nCk = n! / (k! * (n-k)!).
+pub(crate) fn chooses(n: u64) -> Vec<u64> {
+    todo!()
+}
+
+/// Returns the "zip" of two vectors.
+///
+/// For instance, `zip(vec![1, 2, 3], vec![4, 5])` equals to `vec![(1, 4), (2, 5)]`.
+/// Here, `3` is ignored because it doesn't have a partner.
+pub(crate) fn zip(lhs: Vec<u64>, rhs: Vec<u64>) -> Vec<(u64, u64)> {
+    todo!()
+}
+
+/// 2x2 matrix of the following configuration:
+///
+/// a, b
+/// c, d
+#[derive(Debug, Clone, Copy)]
+struct Mat2 {
+    a: u64,
+    b: u64,
+    c: u64,
+    d: u64,
+}
+
+/// 2x1 matrix of the following configuration:
+///
+/// a
+/// b
+#[derive(Debug, Clone, Copy)]
+struct Vec2 {
+    a: u64,
+    b: u64,
+}
+
+impl Mat2 {
+    /// Creates an identity matrix.
+    fn new() -> Self {
+        Self {
+            a: 1,
+            b: 0,
+            c: 0,
+            d: 1,
+        }
+    }
+}
+
+impl Mul<Mat2> for Mat2 {
+    type Output = Mat2;
+
+    fn mul(self, rhs: Mat2) -> Self::Output {
+        todo!()
+    }
+}
+
+impl Mul<Vec2> for Mat2 {
+    type Output = Vec2;
+
+    fn mul(self, rhs: Vec2) -> Self::Output {
+        todo!()
+    }
+}
+
+impl Mat2 {
+    /// Calculates the power of matrix.
+    fn power(self, power: u64) -> Mat2 {
+        todo!()
+    }
+}
+
+impl Vec2 {
+    /// Gets the upper value of vector.
+    fn get_upper(self) -> u64 {
+        todo!()
+    }
+}
+
+/// The matrix used for calculating Fibonacci numbers.
+const FIBONACCI_MAT: Mat2 = Mat2 {
+    a: 1,
+    b: 1,
+    c: 1,
+    d: 0,
+};
+
+/// The vector used for calculating Fibonacci numbers.
+const FIBONACCI_VEC: Vec2 = Vec2 { a: 1, b: 0 };
+
+/// Calculates the Fibonacci number.
+///
+/// Consult <https://web.media.mit.edu/~holbrow/post/calculating-fibonacci-numbers-with-matrices-and-linear-algebra/> for matrix computation of Fibonacci numbers.
+pub(crate) fn fibonacci(n: u64) -> u64 {
+    (FIBONACCI_MAT.power(n) * FIBONACCI_VEC).get_upper()
+}
+
+/// Writes down the lyrics of "twelve days of christmas".
+///
+/// Hint: Google the song title for lyrics and look at the test code for the expected result.
+pub(crate) fn twelve_days_of_christmas_lyrics() -> String {
+    todo!()
+}

src/assignments/assignment02_grade.rs

@@ -1,4 +1,168 @@
 #[cfg(test)]
 mod test {
     use super::super::assignment02::*;
+
+    #[test]
+    fn test_farenheit() {
+        assert_eq!(farhenheit_to_celcius(32.0), 0.0);
+        assert_eq!(farhenheit_to_celcius(212.0), 100.0);
+    }
+
+    #[test]
+    fn test_capitalize() {
+        assert_eq!(
+            capitalize(String::from("aAbbBcccCddddD❤한글과✓")),
+            String::from("AABBBCCCCDDDDD❤한글과✓"),
+        );
+    }
+
+    #[test]
+    fn test_up3() {
+        assert_eq!(up3(6), 9);
+        assert_eq!(up3(9), 9);
+        assert_eq!(up3(10), 27);
+        assert_eq!(up3(1_000_000), 1_594_323);
+    }
+
+    #[test]
+    fn test_sum_array() {
+        assert_eq!(sum_array(&[1, 2, 3, 4, 5, 100]), 115);
+    }
+
+    #[test]
+    fn test_chooses() {
+        assert_eq!(chooses(5), vec![1, 5, 10, 10, 5, 1]);
+        assert_eq!(chooses(6), vec![1, 6, 15, 20, 15, 6, 1]);
+    }
+
+    #[test]
+    fn test_zip() {
+        assert_eq!(zip(vec![1, 2], vec![4, 5]), vec![(1, 4), (2, 5)]);
+        assert_eq!(zip(vec![1, 2, 3], vec![4, 5]), vec![(1, 4), (2, 5)]);
+        assert_eq!(zip(vec![1, 2], vec![4, 5, 6]), vec![(1, 4), (2, 5)]);
+        assert_eq!(zip(vec![], vec![4, 5]), vec![]);
+    }
+
+    #[test]
+    fn test_fibonacci() {
+        assert_eq!(fibonacci(0), 1);
+        assert_eq!(fibonacci(1), 1);
+        assert_eq!(fibonacci(2), 2);
+        assert_eq!(fibonacci(3), 3);
+        assert_eq!(fibonacci(4), 5);
+        assert_eq!(fibonacci(5), 8);
+        assert_eq!(fibonacci(6), 13);
+        assert_eq!(fibonacci(7), 21);
+        assert_eq!(fibonacci(50), 20365011074);
+    }
+
+    #[test]
+    fn test_lyrics() {
+        assert_eq!(twelve_days_of_christmas_lyrics(), LYRICS)
+    }
+
+    const LYRICS: &str = r#"On the first day of Christmas, my true love sent to me
+A partridge in a pear tree
+
+On the second day of Christmas, my true love sent to me
+Two turtledoves
+And a partridge in a pear tree
+
+On the third day of Christmas, my true love sent to me
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the fourth day of Christmas, my true love sent to me
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the fifth day of Christmas, my true love sent to me
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the sixth day of Christmas, my true love sent to me
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the seventh day of Christmas, my true love sent to me
+Seven swans a-swimming
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the eighth day of Christmas, my true love sent to me
+Eight maids a-milking
+Seven swans a-swimming
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the ninth day of Christmas, my true love sent to me
+Nine ladies dancing
+Eight maids a-milking
+Seven swans a-swimming
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the tenth day of Christmas, my true love sent to me
+Ten lords a-leaping
+Nine ladies dancing
+Eight maids a-milking
+Seven swans a-swimming
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the eleventh day of Christmas, my true love sent to me
+I sent eleven pipers piping
+Ten lords a-leaping
+Nine ladies dancing
+Eight maids a-milking
+Seven swans a-swimming
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+On the twelfth day of Christmas, my true love sent to me
+Twelve drummers drumming
+Eleven pipers piping
+Ten lords a-leaping
+Nine ladies dancing
+Eight maids a-milking
+Seven swans a-swimming
+Six geese a-laying
+Five gold rings (five golden rings)
+Four calling birds
+Three French hens
+Two turtledoves
+And a partridge in a pear tree
+
+And a partridge in a pear tree
+"#;
 }

src/assignments/mod.rs

@@ -3,3 +3,5 @@
 
 mod assignment01;
 mod assignment01_grade;
+mod assignment02;
+mod assignment02_grade;