Package g1601_1700.s1654_minimum_jumps_to_reach_home

Class Solution

java.lang.Object
g1601_1700.s1654_minimum_jumps_to_reach_home.Solution
public class Solution extends java.lang.Object
1654 - Minimum Jumps to Reach Home.

Medium

A certain bug’s home is on the x-axis at position x. Help them get there from position 0.

The bug jumps according to the following rules:

  • It can jump exactly a positions forward (to the right).
  • It can jump exactly b positions backward (to the left).
  • It cannot jump backward twice in a row.
  • It cannot jump to any forbidden positions.

The bug may jump forward beyond its home, but it cannot jump to positions numbered with negative integers.

Given an array of integers forbidden, where forbidden[i] means that the bug cannot jump to the position forbidden[i], and integers a, b, and x, return the minimum number of jumps needed for the bug to reach its home. If there is no possible sequence of jumps that lands the bug on position x, return -1.

Example 1:

Input: forbidden = [14,4,18,1,15], a = 3, b = 15, x = 9

Output: 3

Explanation: 3 jumps forward (0 -> 3 -> 6 -> 9) will get the bug home.

Example 2:

Input: forbidden = [8,3,16,6,12,20], a = 15, b = 13, x = 11

Output: -1

Example 3:

Input: forbidden = [1,6,2,14,5,17,4], a = 16, b = 9, x = 7

Output: 2

Explanation: One jump forward (0 -> 16) then one jump backward (16 -> 7) will get the bug home.

Constraints:

  • 1 <= forbidden.length <= 1000
  • 1 <= a, b, forbidden[i] <= 2000
  • 0 <= x <= 2000
  • All the elements in forbidden are distinct.
  • Position x is not forbidden.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    minimumJumps(int[] forbidden, int a, int b, int x)
     

    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

    • minimumJumps

      public int minimumJumps(int[] forbidden, int a, int b, int x)