-- practice 6

src/practice/mod.rs

@@ -1 +1,2 @@
 mod p05;
+mod p06;

src/practice/p06/envelope.rs

@@ -0,0 +1,113 @@
+#[test]
+fn test20() {
+    const W: u32 = 10;
+    const H: u32 = 10;
+
+    for y in 0..H {
+        for x in 0..W {
+            let c = if y == 0 || y == H - 1 || x == 0 || x == W - 1 || x == y || x == H - 1 - y {
+                '*'
+            } else {
+                ' '
+            };
+            print!("{}", c);
+        }
+        println!();
+    }
+}
+
+#[test]
+fn test21() {
+    const W: u32 = 10;
+    const H: u32 = 10;
+
+    for y in 0..H {
+        for x in 0..W {
+            let is_horizontal = y == 0 || y == H - 1;
+            let is_vertical = x == 0 || x == W - 1;
+            let id_diagonal = x == y;
+            let id_co_diagonal = x == W - 1 - y;
+
+            let c = if is_horizontal || is_vertical || id_diagonal || id_co_diagonal {
+                '*'
+            } else {
+                ' '
+            };
+            print!("{}", c);
+        }
+        println!();
+    }
+}
+
+#[test]
+fn test22() {
+    const W: u32 = 25;
+    const H: u32 = 10;
+    let k = W / H; // 2
+
+    for y in 0..H {
+        for x in 0..W {
+            let is_horizontal = y == 0 || y == H - 1;
+            let is_vertical = x == 0 || x == W - 1;
+            let id_diagonal = x == y * k;
+            let id_co_diagonal = x == W - 1 - y * k;
+
+            let c = if is_horizontal || is_vertical || id_diagonal || id_co_diagonal {
+                '*'
+            } else {
+                ' '
+            };
+            print!("{}", c);
+        }
+        println!();
+    }
+}
+
+#[test]
+fn test23() {
+    const W: u32 = 25;
+    const H: u32 = 10;
+    let k = W as f32 / H as f32; // 2.5
+
+    for y in 0..H {
+        for x in 0..W {
+            let is_horizontal = y == 0 || y == H - 1;
+            let is_vertical = x == 0 || x == W - 1;
+            let id_diagonal = x == (y as f32 * k) as u32;
+            let id_co_diagonal = x == W - 1 - (y as f32 * k) as u32;
+
+            let c = if is_horizontal || is_vertical || id_diagonal || id_co_diagonal {
+                '*'
+            } else {
+                ' '
+            };
+            print!("{}", c);
+        }
+        println!();
+    }
+}
+
+#[test]
+fn test24() {
+    const W: u32 = 25;
+    const H: u32 = 10;
+    let k = W as f32 / H as f32; // 2.5
+
+    fn mul(a: u32, b: f32) -> u32 {
+        (a as f32 * b) as u32
+    }
+
+    for y in 1..=H {
+        for x in 1..=W {
+            let c: char = match (x, y) {
+                (_, 1 | H) => '-',
+                (1 | W, _) => '|',
+                _ if x == mul(y, k) => '\\',
+                _ if x == W - mul(y, k) => '/',
+                _ => ' ',
+            };
+            print!("{}", c);
+        }
+        println!();
+    }
+}

src/practice/p06/mod.rs

@@ -0,0 +1 @@
+mod envelope;