Odd Even Jump LeetCode solution in Java

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class Solution {
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  public int oddEvenJumps(int[] arr) {
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    int len = arr.length;
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    int minjmp[] = new int[len];
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    int maxjmp[] = new int[len];
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    TreeMap<Integer, Integer> map = new TreeMap<>();
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    int evjmp, oddjmp;
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    for (int i = len - 1; i >= 0; i--) {
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      Integer minpos = map.floorKey(arr[i]);
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      evjmp = (minpos != null) ? map.get(minpos) : len; // default len, to show not possible
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      if (evjmp != len && (evjmp == len - 1 || maxjmp[evjmp] == len - 1))
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        evjmp = len - 1; // check the last pos reachability
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      Integer maxpos = map.ceilingKey(arr[i]);
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      oddjmp = (maxpos != null) ? map.get(maxpos) : len;
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      if (oddjmp != len && (oddjmp == len - 1 || minjmp[oddjmp] == len - 1))
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        oddjmp = len - 1; // check the last pos reachability
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      minjmp[i] = evjmp; // specify possible jump path, if not possible assign len
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      maxjmp[i] = oddjmp; // specify possible jump path, if not possible assign len
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      map.put(arr[i], i); // put the current index
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    }
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    int res = 0;
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    for (int i = 0; i < len - 1; i++) {
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      if (maxjmp[i] == len - 1) res++;
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    }
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    return res + 1; // since last position will always be the answer
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  }
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}