From 1e54bc61e81a81b0647325f724690b376de50a2a Mon Sep 17 00:00:00 2001 From: Sateesh Basavaraju Date: Fri, 4 Jun 2021 16:09:12 +0530 Subject: [PATCH] feat: Add hashmap3 exercise. --- exercises/hashmaps/hashmaps3.rs | 88 +++++++++++++++++++++++++++++++++ info.toml | 12 +++++ 2 files changed, 100 insertions(+) create mode 100644 exercises/hashmaps/hashmaps3.rs diff --git a/exercises/hashmaps/hashmaps3.rs b/exercises/hashmaps/hashmaps3.rs new file mode 100644 index 0000000..60293f2 --- /dev/null +++ b/exercises/hashmaps/hashmaps3.rs @@ -0,0 +1,88 @@ +// hashmaps3.rs + +// A list of scores (one per line) of a soccer match is given. Each line +// is of the form : +// ,,, +// Example: England,France,4,2 (England scored 4 goals, France 2). + +// You have to build a scores table containing the name of the team, goals +// the team scored, and goals the team conceded. One approach to build +// the scores table is to use a Hashmap. The solution is partially +// written to use a Hashmap, complete it to pass the test. + +// Make me pass the tests! + +// Execute the command `rustlings hint hashmap3` if you need +// hints. + +// I AM NOT DONE + +use std::collections::HashMap; + +// A structure to store team name and its goal details. +struct Team { + name: String, + goals_scored: u8, + goals_conceded: u8, +} + +fn build_scores_table(results: String) -> HashMap { + // The name of the team is the key and its associated struct is the value. + let mut scores: HashMap = HashMap::new(); + + for r in results.lines() { + let v: Vec<&str> = r.split(',').collect(); + let team_1_name = v[0].to_string(); + let team_1_score: u8 = v[2].parse().unwrap(); + let team_2_name = v[1].to_string(); + let team_2_score: u8 = v[3].parse().unwrap(); + // TODO: Populate the scores table with details extracted from the + // current line. Keep in mind that goals scored by team_1 + // 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. + } + scores +} + +#[cfg(test)] +mod tests { + use super::*; + + fn get_results() -> String { + let results = "".to_string() + + "England,France,4,2\n" + + "France,Italy,3,1\n" + + "Poland,Spain,2,0\n" + + "Germany,England,2,1\n"; + results + } + + #[test] + fn build_scores() { + let scores = build_scores_table(get_results()); + + let mut keys: Vec<&String> = scores.keys().collect(); + keys.sort(); + assert_eq!( + keys, + vec!["England", "France", "Germany", "Italy", "Poland", "Spain"] + ); + } + + #[test] + fn validate_team_score_1() { + let scores = build_scores_table(get_results()); + let team = scores.get("England").unwrap(); + assert_eq!(team.goals_scored, 5); + assert_eq!(team.goals_conceded, 4); + } + + #[test] + fn validate_team_score_2() { + let scores = build_scores_table(get_results()); + let team = scores.get("Spain").unwrap(); + assert_eq!(team.goals_scored, 0); + assert_eq!(team.goals_conceded, 2); + } +} diff --git a/info.toml b/info.toml index c54672b..ec2d817 100644 --- a/info.toml +++ b/info.toml @@ -506,6 +506,18 @@ Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this. Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value """ +[[exercises]] +name = "hashmaps3" +path = "exercises/hashmaps/hashmaps3.rs" +mode = "test" +hint = """ +Hint 1: Use the `entry()` and `or_insert()` methods of `HashMap` to insert entries corresponding to each team in the scores table. +Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value +Hint 2: If there is already an entry for a given key, the value returned by `entry()` can be updated based on the existing value. +Learn more at https://doc.rust-lang.org/book/ch08-03-hash-maps.html#updating-a-value-based-on-the-old-value +""" + + # TEST 2 [[exercises]]