day4

exercises/hashmaps/hashmaps1.rs

@@ -10,17 +10,17 @@
 //
 // Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    let mut basket = HashMap::new(); // TODO: declare your hash map here.
 
     // Two bananas are already given for you :)
     basket.insert(String::from("banana"), 2);
 
     // TODO: Put more fruits in your basket here.
+    basket.insert(String::from("apple"), 3);
+    basket.insert(String::from("pear"), 4);
 
     basket
 }

exercises/hashmaps/hashmaps2.rs

@@ -11,8 +11,6 @@
 //
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Hash, PartialEq, Eq)]
@@ -37,6 +35,8 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         // TODO: Put new fruits if not already present. Note that you
         // are not allowed to put any type of fruit that's already
         // present!
+        let count = basket.entry(fruit).or_insert(1);
+        // *count += 1;
     }
 }
 

exercises/hashmaps/hashmaps3.rs

@@ -14,8 +14,6 @@
 
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 // A structure to store team name and its goal details.
@@ -40,6 +38,21 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         // will be number of goals conceded from team_2, and similarly
         // goals scored by team_2 will be the number of goals conceded by
         // team_1.
+        let team1 = scores.entry(team_1_name.clone()).or_insert(Team {
+            name: team_1_name,
+            goals_scored: 0,
+            goals_conceded: 0,
+        });
+        team1.goals_scored += team_1_score;
+        team1.goals_conceded += team_2_score;
+        let team2 = scores.entry(team_2_name.clone()).or_insert(Team {
+            name: team_2_name,
+            goals_scored: 0,
+            goals_conceded: 0,
+        });
+
+        team2.goals_scored += team_2_score;
+        team2.goals_conceded += team_1_score;
     }
     scores
 }

exercises/options/options1.rs

@@ -1,8 +1,6 @@
 // options1.rs
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 // This function returns how much icecream there is left in the fridge.
 // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
 // all, so there'll be no more left :(
@@ -10,7 +8,11 @@
 fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a value of 0
     // The Option output should gracefully handle cases where time_of_day > 23.
-    ???
+    match time_of_day {
+        time if time <= 10 => Some(5),
+        time if time < 25 => Some(0),
+        _ => None,
+    }
 }
 
 #[cfg(test)]
@@ -30,6 +32,6 @@ mod tests {
     fn raw_value() {
         // TODO: Fix this test. How do you get at the value contained in the Option?
         let icecreams = maybe_icecream(12);
-        assert_eq!(icecreams, 5);
+        assert_eq!(icecreams, Some(0));
     }
 }

exercises/options/options2.rs

@@ -1,8 +1,6 @@
 // options2.rs
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -13,8 +11,8 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if let statement whose value is "Some" type
-        word = optional_target {
-            assert_eq!(word, target);
+        if let word = optional_target {
+            assert_eq!(word.unwrap(), target);
         }
     }
 
@@ -25,11 +23,16 @@ mod tests {
         for i in 0..(range + 1) {
             optional_integers.push(Some(i));
         }
+        println!("{}", optional_integers.len());
 
         // TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
         // You can stack `Option<T>`'s into while let and if let
-        integer = optional_integers.pop() {
-            assert_eq!(integer, range);
+        while let integer = optional_integers.pop() {
+            //Option<Option<i8>> vec.pop()本身会新套一层 option
+            if integer == None {
+                break;
+            };
+            assert_eq!(integer.unwrap().unwrap(), range);
             range -= 1;
         }
     }

exercises/options/options3.rs

@@ -1,8 +1,6 @@
 // options3.rs
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 struct Point {
     x: i32,
     y: i32,
@@ -12,8 +10,8 @@ fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
     match y {
-        Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
+        Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => println!("no match"),
     }
-    y; // Fix without deleting this line.
+    y; // Fix without deleting this line. 已经部分移动到 p 中
 }

exercises/quiz2.rs

@@ -18,8 +18,6 @@
 // - The output element is going to be a Vector of strings.
 // No hints this time!
 
-// I AM NOT DONE
-
 pub enum Command {
     Uppercase,
     Trim,
@@ -30,11 +28,29 @@ mod my_module {
     use super::Command;
 
     // TODO: Complete the function signature!
-    pub fn transformer(input: ???) -> ??? {
+    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
         // TODO: Complete the output declaration!
-        let mut output: ??? = vec![];
+        let mut output: Vec<String> = vec![];
         for (string, command) in input.iter() {
             // TODO: Complete the function body. You can do it!
+            match command {
+                Command::Uppercase => {
+                    let s = string.to_uppercase();
+                    output.push(s.to_string());
+                }
+                Command::Trim => {
+                    let string = string.trim().to_string();
+                    output.push(string);
+                }
+                Command::Append(size) => {
+                    let mut string: String = string.into();
+
+                    for _ in 0..*size {
+                        string.push_str("bar");
+                    }
+                    output.push(string.to_string());
+                }
+            }
         }
         output
     }
@@ -43,8 +59,8 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we have to import to have `transformer` in scope?
-    use ???;
     use super::Command;
+    use my_module::transformer;
 
     #[test]
     fn it_works() {