add read_binary_watch (#31)

ChrisLinn · 0xmountaintop · commit a0407f153ea6 · 2019-08-01T18:19:59.000+08:00
diff --git a/README.md b/README.md
@@ -68,10 +68,10 @@ cargo test
 0371 | [Sum of Two Integers](https://leetcode.com/problems/sum-of-two-integers/) | [C++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/sum-of-two-integers.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/Python/sum-of-two-integers.py) <br>------</br> [Rust](./kamyu104/src/sum_of_two_integers.rs) | _O(1)_ | _O(1)_ | Easy | LintCode |
 0389 | [Find the Difference](https://leetcode.com/problems/find-the-difference/) | [C++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/find-the-difference.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/Python/find-the-difference.py) <br>------</br> [Rust](./kamyu104/src/find_the_difference.rs) | _O(n)_ | _O(1)_ | Easy | |
 0393 | [UTF-8 Validation](https://leetcode.com/problems/utf-8-validation/) | [C++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/utf-8-validation.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/Python/utf-8-validation.py) <br>------</br> [Rust](./kamyu104/src/utf_8_validation.rs) | _O(n)_ | _O(1)_ | Medium | |
+0401 | [Binary Watch](https://leetcode.com/problems/binary-watch/) | [C++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/binary-watch.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/Python/binary-watch.py) <br>------</br> [Rust](./kamyu104/src/binary_watch.rs) | _O(1)_ | _O(1)_ | Easy | |
 
 <!-- 
 
-0401 | [Binary Watch](https://leetcode.com/problems/binary-watch/) | [C++](./C++/binary-watch.cpp) [Python](./Python/binary-watch.py) | _O(1)_ | _O(1)_ | Easy | |
 0411 | [Minimum Unique Word Abbreviation](https://leetcode.com/problems/minimum-unique-word-abbreviation/) | [C++](./C++/minimum-unique-word-abbreviation.cpp) [Python](./Python/minimum-unique-word-abbreviation.py) | _O(2^n)_ | _O(n)_ | Hard | 🔒 |
 0421 | [Maximum XOR of Two Numbers in an Array](https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array/) | [C++](./C++/maximum-xor-of-two-numbers-in-an-array.cpp) [Python](./Python/maximum-xor-of-two-numbers-in-an-array.py) | _O(n)_ | _O(n)_ | Medium ||
 0461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance/) | [C++](./C++/hamming-distance.cpp) [Python](./Python/hamming-distance.py) | _O(1)_ | _O(1)_ | Easy ||
diff --git a/kamyu104/src/binary_watch.rs b/kamyu104/src/binary_watch.rs
@@ -0,0 +1,46 @@
+use std::collections::BTreeSet;
+
+// Time:  O(1)
+// Space: O(1)
+
+pub struct Solution {}
+impl Solution {
+    pub fn read_binary_watch(num: i32) -> Vec<String> {
+        let mut result: Vec<String> = Vec::new();
+        (0..12).for_each(|h| {
+            (0..60).for_each(|m| {
+                if (Solution::bit_count(h) + Solution::bit_count(m)) == num {
+                    result.push(format!("{}:{:02}", h, m));
+                }
+            });
+        });
+        result
+    }
+
+    fn bit_count(mut bits: i32) -> i32 {
+        let mut count: i32 = 0;
+        while bits != 0 {
+            count += 1;
+            bits &= bits - 1;
+        }
+        count
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_read_binary_watch() {
+        assert_eq!(
+            Solution::read_binary_watch(1)
+                .into_iter()
+                .collect::<BTreeSet<String>>(),
+            vec!["1:00", "2:00", "4:00", "8:00", "0:01", "0:02", "0:04", "0:08", "0:16", "0:32"]
+                .into_iter()
+                .map(String::from)
+                .collect::<BTreeSet<String>>()
+        );
+    }
+}
diff --git a/kamyu104/src/main.rs b/kamyu104/src/main.rs
@@ -1,3 +1,4 @@
+mod binary_watch;
 mod bitwise_and_of_numbers_range;
 mod find_the_difference;
 mod maximum_product_of_word_lengths;
diff --git a/kamyu104/src/single_number_iii.rs b/kamyu104/src/single_number_iii.rs
@@ -1,3 +1,5 @@
+use std::collections::BTreeSet;
+
 // Time:  O(n)
 // Space: O(1)
 
@@ -49,8 +51,18 @@ mod tests {
 
     #[test]
     fn test_single_number() {
-        assert_eq!(Solution1::single_number(vec![1, 2, 1, 3, 2, 5]), vec![5, 3]);
+        assert_eq!(
+            Solution1::single_number(vec![1, 2, 1, 3, 2, 5])
+                .into_iter()
+                .collect::<BTreeSet<i32>>(),
+            vec![3, 5].into_iter().collect::<BTreeSet<i32>>()
+        );
 
-        assert_eq!(Solution2::single_number(vec![1, 2, 1, 3, 2, 5]), vec![3, 5]);
+        assert_eq!(
+            Solution2::single_number(vec![1, 2, 1, 3, 2, 5])
+                .into_iter()
+                .collect::<BTreeSet<i32>>(),
+            vec![3, 5].into_iter().collect::<BTreeSet<i32>>()
+        );
     }
 }
