update

leetcode/problem/elimination-game.html

@@ -0,0 +1,36 @@
+<p>You have a list <code>arr</code> of all integers in the range <code>[1, n]</code> sorted in a strictly increasing order. Apply the following algorithm on <code>arr</code>:</p>
+
+<ul>
+	<li>Starting from left to right, remove the first number and every other number afterward until you reach the end of the list.</li>
+	<li>Repeat the previous step again, but this time from right to left, remove the rightmost number and every other number from the remaining numbers.</li>
+	<li>Keep repeating the steps again, alternating left to right and right to left, until a single number remains.</li>
+</ul>
+
+<p>Given the integer <code>n</code>, return <em>the last number that remains in</em> <code>arr</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 9
+<strong>Output:</strong> 6
+<strong>Explanation:</strong>
+arr = [<u>1</u>, 2, <u>3</u>, 4, <u>5</u>, 6, <u>7</u>, 8, <u>9</u>]
+arr = [2, <u>4</u>, 6, <u>8</u>]
+arr = [<u>2</u>, 6]
+arr = [6]
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 1
+<strong>Output:</strong> 1
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= n &lt;= 10<sup>9</sup></code></li>
+</ul>