```
public class Solution
extends Object
```
1345 - Jump Game IV\. Hard 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

Class Solution