add leetcode problem-cn part2

算法题（国内版）/problem (English)/配对交换(English) [exchange-lcci].html

@@ -0,0 +1,22 @@
+<p>Write a program to swap odd and even bits in an integer with as few instructions as possible (e.g., bit 0 and bit 1 are swapped, bit 2 and bit 3 are swapped, and so on).</p>
+
+<p><strong>Example1:</strong></p>
+
+<pre>
+<strong> Input</strong>: num = 2（0b10）
+<strong> Output</strong> 1 (0b01)
+</pre>
+
+<p><strong>Example2:</strong></p>
+
+<pre>
+<strong> Input</strong>: num = 3
+<strong> Output</strong>: 3
+</pre>
+
+<p><strong>Note:</strong></p>
+
+<ol>
+	<li><code>0 &lt;= num &lt;=</code>&nbsp;2^30 - 1</li>
+	<li>The result integer fits into 32-bit integer.</li>
+</ol>