Watch 10 video solutions for Jump Game IV, a hard level problem involving Array, Hash Table, Breadth-First Search. This walkthrough by Algorithms Made Easy has 6,861 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given an array of integers arr, you are initially positioned at the first index of the array.
In one step you can jump from index i to index:
i + 1 where: i + 1 < arr.length.i - 1 where: i - 1 >= 0.j where: arr[i] == arr[j] and i != j.Return the minimum number of steps to reach the last index of the array.
Notice that you can not jump outside of the array at any time.
Example 1:
Input: arr = [100,-23,-23,404,100,23,23,23,3,404] Output: 3 Explanation: You need three jumps from index 0 --> 4 --> 3 --> 9. Note that index 9 is the last index of the array.
Example 2:
Input: arr = [7] Output: 0 Explanation: Start index is the last index. You do not need to jump.
Example 3:
Input: arr = [7,6,9,6,9,6,9,7] Output: 1 Explanation: You can jump directly from index 0 to index 7 which is last index of the array.
Constraints:
1 <= arr.length <= 5 * 104-108 <= arr[i] <= 108