rustlings/exercises/hashmaps/hashmaps3.rs

115 lines
3.5 KiB
Rust

// hashmaps3.rs
//
// A list of scores (one per line) of a soccer match is given. Each line is of
// the form : "<team_1_name>,<team_2_name>,<team_1_goals>,<team_2_goals>"
// 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 `rustlings hint hashmaps3` or use the `hint` watch subcommand for a
// hint.
use std::collections::HashMap;
// A structure to store the goal details of a team.
struct Team {
goals_scored: u8,
goals_conceded: u8,
}
fn build_scores_table(results: String) -> HashMap<String, Team> {
// The name of the team is the key and its associated struct is the value.
let mut scores: HashMap<String, Team> = 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 the 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 mut team_1 = Team{
goals_scored: team_1_score,
goals_conceded: team_2_score
};
let mut team_2 = Team{
goals_scored: team_2_score,
goals_conceded: team_1_score
};
match scores.get(&team_1_name) {
None => {scores.insert(team_1_name, team_1);},
Some(t) => {
team_1.goals_scored += t.goals_scored;
team_1.goals_conceded += t.goals_conceded;
scores.insert(team_1_name, team_1);
}
};
match scores.get(&team_2_name) {
None => {scores.insert(team_2_name, team_2);},
Some(t) => {
team_2.goals_scored += t.goals_scored;
team_2.goals_conceded += t.goals_conceded;
scores.insert(team_2_name, team_2);
}
};
}
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);
}
}