Solve keyboard-row.

source/keyboard_row/mod.rs

@@ -0,0 +1,29 @@
+pub fn find_words(words: Vec<String>) -> Vec<String> {
+  // Uncomment FromIterator in Leetcode since they're using Rust Edition 2018.
+  // Edition 2021 has this trait in its prelude.
+
+  // use std::iter::FromIterator;
+  use std::collections::HashSet;
+
+  fn hashset_from_str(string: &str) -> HashSet<char> {
+    std::collections::HashSet::<_>::from_iter(string.to_lowercase().chars())
+  }
+
+  let rows = [
+    hashset_from_str("qwertyuiop"),
+    hashset_from_str("asdfghjkl"),
+    hashset_from_str("zxcvbnm"),
+  ];
+
+  let mut result = vec![];
+
+  for word in words {
+    let word_set = hashset_from_str(&word);
+
+    if rows.iter().any(|row| word_set.is_subset(row)) {
+      result.push(word);
+    }
+  }
+
+  result
+}

source/lib.rs

@@ -6,6 +6,7 @@ pub mod excel_sheet_column_title;
 pub mod implement_strstr;
 pub mod integer_to_roman;
 pub mod isomorphic_strings;
+pub mod keyboard_row;
 pub mod length_of_last_word;
 pub mod longest_common_prefix;
 pub mod missing_number;

tests/keyboard_row.rs

@@ -0,0 +1,13 @@
+use leetcode::keyboard_row::find_words;
+
+use test_case::test_case;
+
+#[test_case(&["Hello", "Alaska", "Dad", "Peace"], &["Alaska", "Dad"]; "example 1")]
+#[test_case(&["omk"], &[]; "example 2")]
+#[test_case(&["adsdf", "sfd"], &["adsdf", "sfd"]; "example 3")]
+fn test_keyboard_row(input: &[&str], expected: &[&str]) {
+  assert_eq!(
+    find_words(input.iter().map(ToString::to_string).collect()),
+    expected
+  );
+}