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.
\n\nNotice that you can not jump outside of the array at any time.
\n\n\n
Example 1:
\n\n\nInput: arr = [100,-23,-23,404,100,23,23,23,3,404]\nOutput: 3\nExplanation: You need three jumps from index 0 --> 4 --> 3 --> 9. Note that index 9 is the last index of the array.\n\n\n
Example 2:
\n\n\nInput: arr = [7]\nOutput: 0\nExplanation: Start index is the last index. You do not need to jump.\n\n\n
Example 3:
\n\n\nInput: arr = [7,6,9,6,9,6,9,7]\nOutput: 1\nExplanation: You can jump directly from index 0 to index 7 which is last index of the array.\n\n\n
\n
Constraints:
\n\n1 <= arr.length <= 5 * 104-108 <= arr[i] <= 108给你一个整数数组 arr ，你一开始在数组的第一个元素处（下标为 0）。
每一步，你可以从下标 i 跳到下标 i + 1 、i - 1 或者 j ：
i + 1 需满足：i + 1 < arr.lengthi - 1 需满足：i - 1 >= 0j 需满足：arr[i] == arr[j] 且 i != j请你返回到达数组最后一个元素的下标处所需的 最少操作次数 。
\n\n注意：任何时候你都不能跳到数组外面。
\n\n\n\n
示例 1：
\n\n\n输入：arr = [100,-23,-23,404,100,23,23,23,3,404]\n输出：3\n解释：那你需要跳跃 3 次，下标依次为 0 --> 4 --> 3 --> 9 。下标 9 为数组的最后一个元素的下标。\n\n\n
示例 2：
\n\n\n输入：arr = [7]\n输出：0\n解释：一开始就在最后一个元素处，所以你不需要跳跃。\n\n\n
示例 3：
\n\n\n输入：arr = [7,6,9,6,9,6,9,7]\n输出：1\n解释：你可以直接从下标 0 处跳到下标 7 处，也就是数组的最后一个元素处。\n\n\n
\n\n
提示：
\n\n\n1 <= arr.length <= 5 * 104-108 <= arr[i] <= 108\\u7248\\u672c\\uff1a \\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 \\u4e3a\\u4e86\\u4f7f\\u7528\\u65b9\\u4fbf\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8\\u5bfc\\u5165\\u3002<\\/p>\"],\"java\":[\"Java\",\" \\u7248\\u672c\\uff1a \\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u88ab\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n \\u5305\\u542b Pair \\u7c7b: https:\\/\\/docs.oracle.com\\/javase\\/8\\/javafx\\/api\\/javafx\\/util\\/Pair.html <\\/p>\"],\"python\":[\"Python\",\" \\u7248\\u672c\\uff1a \\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u5e38\\u7528\\u5e93\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8 \\u5bfc\\u5165\\uff0c\\u5982\\uff1aarray<\\/a>, bisect<\\/a>, collections<\\/a>\\u3002\\u5982\\u679c\\u60a8\\u9700\\u8981\\u4f7f\\u7528\\u5176\\u4ed6\\u5e93\\u51fd\\u6570\\uff0c\\u8bf7\\u81ea\\u884c\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n \\u6ce8\\u610f Python 2.7 \\u5c06\\u57282020\\u5e74\\u540e\\u4e0d\\u518d\\u7ef4\\u62a4<\\/a>\\u3002 \\u5982\\u60f3\\u4f7f\\u7528\\u6700\\u65b0\\u7248\\u7684Python\\uff0c\\u8bf7\\u9009\\u62e9Python 3\\u3002<\\/p>\"],\"c\":[\"C\",\" \\u7248\\u672c\\uff1a \\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 \\u4e3a\\u4e86\\u4f7f\\u7528\\u65b9\\u4fbf\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n \\u5982\\u60f3\\u4f7f\\u7528\\u54c8\\u5e0c\\u8868\\u8fd0\\u7b97, \\u60a8\\u53ef\\u4ee5\\u4f7f\\u7528 uthash<\\/a>\\u3002 \\\"uthash.h\\\"\\u5df2\\u7ecf\\u9ed8\\u8ba4\\u88ab\\u5bfc\\u5165\\u3002\\u8bf7\\u770b\\u5982\\u4e0b\\u793a\\u4f8b:<\\/p>\\r\\n\\r\\n 1. 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