Package g0701_0800.s0775_global_and_local_inversions

Class Solution

java.lang.Object

g0701_0800.s0775_global_and_local_inversions.Solution

public class Solution
extends Object

775 - Global and Local Inversions.<p>Medium</p> <p>You are given an integer array <code>nums</code> of length <code>n</code> which represents a permutation of all the integers in the range <code>[0, n - 1]</code>.</p> <p>The number of <strong>global inversions</strong> is the number of the different pairs <code>(i, j)</code> where:</p> <ul> <li><code>0 <= i < j < n</code></li> <li><code>nums[i] > nums[j]</code></li> </ul> <p>The number of <strong>local inversions</strong> is the number of indices <code>i</code> where:</p> <ul> <li><code>0 <= i < n - 1</code></li> <li><code>nums[i] > nums[i + 1]</code></li> </ul> <p>Return <code>true</code> <em>if the number of <strong>global inversions</strong> is equal to the number of <strong>local inversions</strong></em>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> nums = [1,0,2]</p> <p><strong>Output:</strong> true</p> <p><strong>Explanation:</strong> There is 1 global inversion and 1 local inversion.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> nums = [1,2,0]</p> <p><strong>Output:</strong> false</p> <p><strong>Explanation:</strong> There are 2 global inversions and 1 local inversion.</p> <p><strong>Constraints:</strong></p> <ul> <li><code>n == nums.length</code></li> <li><code>1 <= n <= 10⁵</code></li> <li><code>0 <= nums[i] < n</code></li> <li>All the integers of <code>nums</code> are <strong>unique</strong>.</li> <li><code>nums</code> is a permutation of all the numbers in the range <code>[0, n - 1]</code>.</li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
boolean	isIdealPermutation(int[] nums)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

isIdealPermutation

public boolean isIdealPermutation(int[] nums)