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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:3Explanation: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:0Explanation:Start index is the last index. You don't need to jump.

**Example 3:**

Input:arr = [7,6,9,6,9,6,9,7]Output:1Explanation:You can jump directly from index 0 to index 7 which is last index of the array.

**Example 4:**

Input:arr = [6,1,9]Output:2

**Example 5:**

Input:arr = [11,22,7,7,7,7,7,7,7,22,13]Output:3

**Constraints:**

`1 <= arr.length <= 5 * 10^4`

`-10^8 <= arr[i] <= 10^8`

All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.