g1501_1600.s1562_find_latest_group_of_size_m

Class Solution

java.lang.Object

g1501_1600.s1562_find_latest_group_of_size_m.Solution

public class Solution
extends Object

1562 - Find Latest Group of Size M.

Medium

Given an array arr that represents a permutation of numbers from 1 to n.

You have a binary string of size n that initially has all its bits set to zero. At each step i (assuming both the binary string and arr are 1-indexed) from 1 to n, the bit at position arr[i] is set to 1.

You are also given an integer m. Find the latest step at which there exists a group of ones of length m. A group of ones is a contiguous substring of 1’s such that it cannot be extended in either direction.

Return the latest step at which there exists a group of ones of length exactly m. If no such group exists, return -1.

Example 1:

Input: arr = [3,5,1,2,4], m = 1

Output: 4

Explanation:

Step 1: “00100”, groups: [“1”]

Step 2: “00101”, groups: [“1”, “1”]

Step 3: “10101”, groups: [“1”, “1”, “1”]

Step 4: “11101”, groups: [“111”, “1”]

Step 5: “11111”, groups: [“11111”]

The latest step at which there exists a group of size 1 is step 4.

Example 2:

Input: arr = [3,1,5,4,2], m = 2

Output: -1

Explanation:

Step 1: “00100”, groups: [“1”]

Step 2: “10100”, groups: [“1”, “1”]

Step 3: “10101”, groups: [“1”, “1”, “1”]

Step 4: “10111”, groups: [“1”, “111”]

Step 5: “11111”, groups: [“11111”]

No group of size 2 exists during any step.

Constraints:

• n == arr.length
• 1 <= m <= n <= 105
• 1 <= arr[i] <= n
• All integers in arr are distinct.

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	findLatestStep(int[] arr, int m)

Methods inherited from class java.lang.Object

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

Constructor Detail

Solution

public Solution()

Method Detail

findLatestStep

public int findLatestStep(int[] arr,
                          int m)