coder-xiaomo/leetcode-problemset
1
0
Fork 0
mirror of https://gitee.com/coder-xiaomo/leetcode-problemset synced 2025-09-05 23:41:41 +08:00
Code Issues Projects Releases Wiki Activity GitHub Gitee

update

Browse Source
This commit is contained in:
小墨
2023-06-12 23:05:37 +08:00
parent 96cb474414
commit 952a47471f
107 changed files with 22284 additions and 13277 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
leetcode/problem/semi-ordered-permutation.html Normal file
View File

@@ -0,0 +1,52 @@
<p>You are given a <strong>0-indexed</strong> permutation of <code>n</code> integers <code>nums</code>.</p>
<p>A permutation is called <strong>semi-ordered</strong> if the first number equals <code>1</code> and the last number equals <code>n</code>. You can perform the below operation as many times as you want until you make <code>nums</code> a <strong>semi-ordered</strong> permutation:</p>
<ul>
<li>Pick two adjacent elements in <code>nums</code>, then swap them.</li>
</ul>
<p>Return <em>the minimum number of operations to make </em><code>nums</code><em> a <strong>semi-ordered permutation</strong></em>.</p>
<p>A <strong>permutation</strong> is a sequence of integers from <code>1</code> to <code>n</code> of length <code>n</code> containing each number exactly once.</p>
<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre>
<strong>Input:</strong> nums = [2,1,4,3]
<strong>Output:</strong> 2
<strong>Explanation:</strong> We can make the permutation semi-ordered using these sequence of operations:
1 - swap i = 0 and j = 1. The permutation becomes [1,2,4,3].
2 - swap i = 2 and j = 3. The permutation becomes [1,2,3,4].
It can be proved that there is no sequence of less than two operations that make nums a semi-ordered permutation.
</pre>
<p><strong class="example">Example 2:</strong></p>
<pre>
<strong>Input:</strong> nums = [2,4,1,3]
<strong>Output:</strong> 3
<strong>Explanation:</strong> We can make the permutation semi-ordered using these sequence of operations:
1 - swap i = 1 and j = 2. The permutation becomes [2,1,4,3].
2 - swap i = 0 and j = 1. The permutation becomes [1,2,4,3].
3 - swap i = 2 and j = 3. The permutation becomes [1,2,3,4].
It can be proved that there is no sequence of less than three operations that make nums a semi-ordered permutation.
</pre>
<p><strong class="example">Example 3:</strong></p>
<pre>
<strong>Input:</strong> nums = [1,3,4,2,5]
<strong>Output:</strong> 0
<strong>Explanation:</strong> The permutation is already a semi-ordered permutation.
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>
<ul>
<li><code>2 &lt;= nums.length == n &lt;= 50</code></li>
<li><code>1 &lt;= nums[i]&nbsp;&lt;= 50</code></li>
<li><code>nums is a permutation.</code></li>
</ul>