add hamming_distance (#33)

0xmountaintop · web-flow · commit 6c947eaaa566 · 2019-08-02T16:27:38.000+08:00
diff --git a/README.md b/README.md
@@ -71,10 +71,14 @@ cargo test
 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 | |
 0411 | [~~Minimum Unique Word Abbreviation~~](https://leetcode.com/problems/minimum-unique-word-abbreviation/) | [C++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/minimum-unique-word-abbreviation.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/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++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/maximum-xor-of-two-numbers-in-an-array.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/Python/maximum-xor-of-two-numbers-in-an-array.py) <br>------</br> [Rust](./kamyu104/src/maximum_xor_of_two_numbers_in_an_array.rs) | _O(n)_ | _O(n)_ | Medium ||
+0461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance/) | [C++](https://github.com/kamyu104/LeetCode-Solutions/blob/master/C++/hamming-distance.cpp) [Python](https://github.com/kamyu104/LeetCode-Solutions/blob/master/Python/hamming-distance.py) <br>------</br> [Rust](./kamyu104/src/hamming_distance.rs) | _O(1)_ | _O(1)_ | Easy ||
+
+<!-- 
+
+=======
 
 <!-- 
 
-0461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance/) | [C++](./C++/hamming-distance.cpp) [Python](./Python/hamming-distance.py) | _O(1)_ | _O(1)_ | Easy ||
 0462 | [Minimum Moves to Equal Array Elements II](https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/) | [C++](./C++/minimum-moves-to-equal-array-elements-ii.cpp) [Python](./Python/minimum-moves-to-equal-array-elements-ii.py) | _O(n)_  on average | _O(1)_ | Medium ||
 0477 | [Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/) | [C++](./C++/total-hamming-distance.cpp) [Python](./Python/total-hamming-distance.py) | _O(n)_ | _O(1)_ | Medium ||
 0645 | [Set Mismatch](https://leetcode.com/problems/set-mismatch/) | [C++](./C++/set-mismatch.cpp) [Python](./Python/set-mismatch.py) | _O(n)_ | _O(1)_ | Easy ||
diff --git a/kamyu104/src/hamming_distance.rs b/kamyu104/src/hamming_distance.rs
@@ -0,0 +1,34 @@
+// Time:  O(1)
+// Space: O(1)
+
+pub struct Solution1 {}
+impl Solution1 {
+    pub fn hamming_distance(x: i32, y: i32) -> i32 {
+        let mut distance: i32 = 0;
+        let mut z: i32 = x ^ y;
+        while z != 0 {
+            distance += 1;
+            z &= z - 1;
+        }
+        distance
+    }
+}
+
+pub struct Solution2 {}
+impl Solution2 {
+    pub fn hamming_distance(x: i32, y: i32) -> i32 {
+        let z = format!("{:b}", x ^ y);
+        z.chars().filter(|&c| c == '1').count() as i32
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_hamming_distance() {
+        assert_eq!(Solution1::hamming_distance(1, 4), 2);
+        assert_eq!(Solution2::hamming_distance(1, 4), 2);
+    }
+}
diff --git a/kamyu104/src/main.rs b/kamyu104/src/main.rs
@@ -1,6 +1,7 @@
 mod binary_watch;
 mod bitwise_and_of_numbers_range;
 mod find_the_difference;
+mod hamming_distance;
 mod maximum_product_of_word_lengths;
 mod maximum_xor_of_two_numbers_in_an_array;
 mod missing_number;
