feat: add solutions to lc problem: No.0461. Hamming Distance

Author: maolonglong

solution/0400-0499/0461.Hamming Distance/README.md

@@ -33,22 +33,55 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+利用异或运算的规律找出不同的位
+
+- 0 ^ 0 = 0
+- 1 ^ 1 = 0
+- 0 ^ 1 = 1
+- 1 ^ 0 = 1
+
 <!-- tabs:start -->
 
 ### **Python3**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
-
+class Solution:
+    def hammingDistance(self, x: int, y: int) -> int:
+        num, count = x ^ y, 0
+        while num != 0:
+            num &= num - 1
+            count += 1
+        return count
 ```
 
 ### **Java**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```java
+class Solution {
+    public int hammingDistance(int x, int y) {
+        int num = x ^ y;
+        int count = 0;
+        while (num != 0) {
+            num &= num - 1;
+            count++;
+        }
+        return count;
+    }
+}
+```
+
+或者利用库函数 `Integer.bitCount()`
 
+```java
+class Solution {
+    public int hammingDistance(int x, int y) {
+        return Integer.bitCount(x ^ y);
+    }
+}
 ```
 
 ### **...**

solution/0400-0499/0461.Hamming Distance/README_EN.md

@@ -38,18 +38,51 @@ The above arrows point to positions where the corresponding bits are different.
 
 ## Solutions
 
+Use xor operation to find different bits.
+
+- 0 ^ 0 = 0
+- 1 ^ 1 = 0
+- 0 ^ 1 = 1
+- 1 ^ 0 = 1
+
 <!-- tabs:start -->
 
 ### **Python3**
 
 ```python
-
+class Solution:
+    def hammingDistance(self, x: int, y: int) -> int:
+        num, count = x ^ y, 0
+        while num != 0:
+            num &= num - 1
+            count += 1
+        return count
 ```
 
 ### **Java**
 
 ```java
+class Solution {
+    public int hammingDistance(int x, int y) {
+        int num = x ^ y;
+        int count = 0;
+        while (num != 0) {
+            num &= num - 1;
+            count++;
+        }
+        return count;
+    }
+}
+```
+
+Or use the library function `Integer.bitCount()`
 
+```java
+class Solution {
+    public int hammingDistance(int x, int y) {
+        return Integer.bitCount(x ^ y);
+    }
+}
 ```
 
 ### **...**

solution/0400-0499/0461.Hamming Distance/Solution.java

@@ -1,10 +1,12 @@
 class Solution {
     public int hammingDistance(int x, int y) {
-        int count = 0, sum = x ^ y;
-        while (sum != 0) {
-            sum &= (sum - 1);
+        // return Integer.bitCount(x ^ y);
+        int num = x ^ y;
+        int count = 0;
+        while (num != 0) {
+            num &= num - 1;
             count++;
         }
         return count;
     }
-}
+}

solution/0400-0499/0461.Hamming Distance/Solution.py

@@ -0,0 +1,7 @@
+class Solution:
+    def hammingDistance(self, x: int, y: int) -> int:
+        num, count = x ^ y, 0
+        while num != 0:
+            num &= num - 1
+            count += 1
+        return count