Package g1501_1600.s1503_last_moment_before_all_ants_fall_out_of_a_plank

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    1503 - Last Moment Before All Ants Fall Out of a Plank.

    Medium

    We have a wooden plank of the length n units. Some ants are walking on the plank, each ant moves with a speed of 1 unit per second. Some of the ants move to the left , the other move to the right.

    When two ants moving in two different directions meet at some point, they change their directions and continue moving again. Assume changing directions does not take any additional time.

    When an ant reaches one end of the plank at a time t, it falls out of the plank immediately.

    Given an integer n and two integer arrays left and right, the positions of the ants moving to the left and the right, return the moment when the last ant(s) fall out of the plank.

    Example 1:

    Input: n = 4, left = 4,3, right = 0,1

    Output: 4

    Explanation: In the image above:

    -The ant at index 0 is named A and going to the right.

    -The ant at index 1 is named B and going to the right.

    -The ant at index 3 is named C and going to the left.

    -The ant at index 4 is named D and going to the left.

    The last moment when an ant was on the plank is t = 4 seconds. After that, it falls immediately out of the plank. (i.e., We can say that at t = 4.0000000001, there are no ants on the plank).

    Example 2:

    Input: n = 7, left = [], right = 0,1,2,3,4,5,6,7

    Output: 7

    Explanation: All ants are going to the right, the ant at index 0 needs 7 seconds to fall.

    Example 3:

    Input: n = 7, left = 0,1,2,3,4,5,6,7, right = []

    Output: 7

    Explanation: All ants are going to the left, the ant at index 7 needs 7 seconds to fall.

    Constraints:

    • <code>1 <= n <= 10<sup>4</sup></code>

    • 0 &lt;= left.length &lt;= n + 1

    • 0 &lt;= left[i] &lt;= n

    • 0 &lt;= right.length &lt;= n + 1

    • 0 &lt;= right[i] &lt;= n

    • 1 &lt;= left.length + right.length &lt;= n + 1

    • All values of left and right are unique, and each value can appear only in one of the two arrays.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer getLastMoment(Integer n, IntArray left, IntArray right)

      • Methods inherited from class java.lang.Object

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