From 3316c2c6d60a57d0a69d236d1a2b50aad89cd617 Mon Sep 17 00:00:00 2001
From: Riccardo Doveri <riccardo.doveri.1998@gmail.com>
Date: Thu, 14 Apr 2022 23:14:02 +0200
Subject: [PATCH] Create 191-Number-of-1-Bits.java

---
 java/191-Number-of-1-Bits.java | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 java/191-Number-of-1-Bits.java

diff --git a/java/191-Number-of-1-Bits.java b/java/191-Number-of-1-Bits.java
new file mode 100644
index 000000000..ac8a605c1
--- /dev/null
+++ b/java/191-Number-of-1-Bits.java
@@ -0,0 +1,28 @@
+//standard way
+public class Solution {
+    // you need to treat n as an unsigned value
+    public int hammingWeight(int n) {
+        int count = 0;
+        int mask = 1;
+        for (int i = 0; i < 32; i++) {
+            if ((n & mask) != 0) {
+                count++;
+            }
+            n >>= 1;
+        }
+        return count;
+    }
+}
+
+//smart way
+public class Solution {
+    // you need to treat n as an unsigned value
+    public int hammingWeight(int n) {
+        int count = 0;
+        while (n != 0) {
+            n = n & (n - 1);
+            count++;
+        }
+        return count;
+    }
+}