From 453505acac5bef7f7d5a94bc0f509ade38f7b2b8 Mon Sep 17 00:00:00 2001
From: Jer3myYu <jeremyyucareer@gmail.com>
Date: Thu, 6 Feb 2025 11:18:59 -0500
Subject: [PATCH 1/4] add: HammingWeightsOfIntegers

---
 .../HammingWeightsOfIntegers.java             | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 java/Bit Manipulation/HammingWeightsOfIntegers.java

diff --git a/java/Bit Manipulation/HammingWeightsOfIntegers.java b/java/Bit Manipulation/HammingWeightsOfIntegers.java
new file mode 100644
index 0000000..c781853
--- /dev/null
+++ b/java/Bit Manipulation/HammingWeightsOfIntegers.java	
@@ -0,0 +1,23 @@
+import java.util.Arrays;
+
+public class HammingWeightsOfIntegers {
+    public hammingWeightsOfIntegers(int n) {
+        int[] res = new int[n + 1];
+        for (int i = 0; i < n + 1; i++) {
+            res[i] = countSetBits(i);
+        }
+        return res;
+    }
+
+    private int countSetBits(int x) {
+        int count = 0;
+        // Count each set bit of 'x' until 'x' equals 0.
+        while (x > 0) {
+            // Increment the count if the LSB is 1.
+            count += x & 1;
+            // Right shift 'x' to shift the next bit to the LSB position.
+            x >>= 1;
+        }
+        return count;
+    }
+}

From e05741647f61829ffb2823e0eb159bbe4ee3b74f Mon Sep 17 00:00:00 2001
From: Jer3myYu <jeremyyucareer@gmail.com>
Date: Thu, 6 Feb 2025 11:22:23 -0500
Subject: [PATCH 2/4] add: HammingWeightsOfIntegersDp and fix minor error in
 HammingWeightsOfIntegers

---
 java/Bit Manipulation/HammingWeightsOfIntegers.java |  8 +++-----
 .../HammingWeightsOfIntegersDp.java                 | 13 +++++++++++++
 2 files changed, 16 insertions(+), 5 deletions(-)
 create mode 100644 java/Bit Manipulation/HammingWeightsOfIntegersDp.java

diff --git a/java/Bit Manipulation/HammingWeightsOfIntegers.java b/java/Bit Manipulation/HammingWeightsOfIntegers.java
index c781853..4227434 100644
--- a/java/Bit Manipulation/HammingWeightsOfIntegers.java	
+++ b/java/Bit Manipulation/HammingWeightsOfIntegers.java	
@@ -1,10 +1,8 @@
-import java.util.Arrays;
-
 public class HammingWeightsOfIntegers {
-    public hammingWeightsOfIntegers(int n) {
+    public int[] hammingWeightsOfIntegers(int n) {
         int[] res = new int[n + 1];
-        for (int i = 0; i < n + 1; i++) {
-            res[i] = countSetBits(i);
+        for (int x = 0; x < n + 1; x++) {
+            res[x] = countSetBits(x);
         }
         return res;
     }
diff --git a/java/Bit Manipulation/HammingWeightsOfIntegersDp.java b/java/Bit Manipulation/HammingWeightsOfIntegersDp.java
new file mode 100644
index 0000000..63793d7
--- /dev/null
+++ b/java/Bit Manipulation/HammingWeightsOfIntegersDp.java	
@@ -0,0 +1,13 @@
+public class HammingWeightsOfIntegersDp {
+    public int[] hammingWeightsOfIntegersDp(int n) {
+        // Base case: the number of set bits in 0 is just 0. We set dp[0] to 
+        // 0 by initializing the entire DP array to 0.
+        int[] dp = new int[n + 1];
+        for (int x = 0; x < n + 1; x++) {
+            // 'dp[x]' is obtained using the result of 'dp[x >> 1]', plus 
+            // the LSB of 'x'.
+            dp[x] = dp[x >> 1] + (x & 1);
+        }
+        return dp;
+    }
+}

From 9655bef4d91e4c60eed01493075dd496c5f2c1a9 Mon Sep 17 00:00:00 2001
From: Jer3myYu <jeremyyucareer@gmail.com>
Date: Thu, 6 Feb 2025 11:25:22 -0500
Subject: [PATCH 3/4] add: LonelyInteger

---
 java/Bit Manipulation/LonelyInteger.java | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 java/Bit Manipulation/LonelyInteger.java

diff --git a/java/Bit Manipulation/LonelyInteger.java b/java/Bit Manipulation/LonelyInteger.java
new file mode 100644
index 0000000..aa81f29
--- /dev/null
+++ b/java/Bit Manipulation/LonelyInteger.java	
@@ -0,0 +1,13 @@
+public class LonelyInteger {
+    public int lonelyInteger(int[] nums) {
+        int res = 0;
+        // XOR each element of the array so that duplicate values will 
+        // cancel each other out (x ^ x == 0).
+        for (int num : nums) {
+            res ^= num;
+        }
+        // 'res' will store the lonely integer because it would not have 
+        // been canceled out by any duplicate.
+        return res;
+    }
+}

From 1c5fcfd1b64e60ce2d5a48f2e8352ee8af4538e8 Mon Sep 17 00:00:00 2001
From: Jer3myYu <jeremyyucareer@gmail.com>
Date: Thu, 6 Feb 2025 11:32:37 -0500
Subject: [PATCH 4/4] add: SwapOddAndEvenBits

---
 java/Bit Manipulation/SwapOddAndEvenBits.java | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 java/Bit Manipulation/SwapOddAndEvenBits.java

diff --git a/java/Bit Manipulation/SwapOddAndEvenBits.java b/java/Bit Manipulation/SwapOddAndEvenBits.java
new file mode 100644
index 0000000..3530140
--- /dev/null
+++ b/java/Bit Manipulation/SwapOddAndEvenBits.java	
@@ -0,0 +1,11 @@
+public class SwapOddAndEvenBits {
+    public int swapOddAndEvenBits(int n) {
+        int evenMask = 0x55555555; // 01010101010101010101010101010101
+        int oddMask = 0xAAAAAAAA;  // 10101010101010101010101010101010
+        int evenBits = n & evenMask;
+        int oddBits = n & oddMask;
+        // Shift the even bits to the left, the odd bits to the right, and 
+        // merge these shifted values together.
+        return (evenBits << 1) | (oddBits >> 1);
+    }
+}