Solve number-of-1-bits

Author: OstenHun

number-of-1-bits/OstenHun.cpp

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+/*
+    191. Number of 1 Bits
+
+    Given a positive integer n, write a function 
+    that returns the number of set bits in its binary representation 
+    (also known as the Hamming weight).
+
+    Example 1:
+        Input: n = 11
+        Output: 3
+
+    Explanation:
+        The input binary string 1011 has a total of three set bits.     
+    
+    Constraints:
+        1 <= n <= 2^31 - 1
+*/
+
+// 비트 연산을 이용하여 풀기
+#include <iostream>
+using namespace std;
+
+class Solution {
+public:
+    int hammingweight(int n) {
+        unsigned int answer = 0;
+        while(n>0) {
+            if (n & 1)
+                answer++;
+            n = n >> 1;
+        }
+        return answer;
+    }
+};
+
+int main() {
+    int n;
+    cin >> n;
+    Solution s;
+
+    cout << s.hammingweight(n);
+}