From 7cd57aa4b13b37604014233d9668f1f876a697e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=94=90=E6=A0=91=E6=A3=AE?= <14021051@buaa.edu.cn>
Date: Tue, 23 Oct 2018 00:00:03 +0800
Subject: [PATCH] Create 190. Reverse Bits.md

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 190. Reverse Bits.md | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 190. Reverse Bits.md

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+# [190. Reverse Bits](https://leetcode.com/problems/reverse-bits/description/)
+# 思路
+将给定的数的二进制进行翻转。    
+定义res为32位无符号型且初始值为0，可从低位到高位依次取得给定的数的32位bit值，再用或运算赋值给res的最低位，res不断左移。     
+可将给定的数与一个mask进行与操作取得特定位数上的值，mask只有一位是1。可通过对mask移位(如下代码)或者对给定的数移位来达到取特定位的目的。 
+# C++
+```
+class Solution {
+public:
+    uint32_t reverseBits(uint32_t n) {
+        uint32_t res = 0;
+        uint32_t mask = 1;
+        for (uint32_t i = 0; i < 32; ++i) {
+            // n & mask取得第i位
+            res = (res << 1) | ((n & mask) >> i);
+            mask = mask << 1;
+        }
+        return res;
+    }
+};
+```