Longest Mountain in Array LeetCode solution in Java

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class Solution {
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  public int longestMountain(int[] arr) {
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    if (arr.length < 3) return 0;
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    int max = 0;
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    for (int i = 0; i < arr.length; i++) {
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      if (isPeak(arr, i)) {
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        int leftLength = left(arr, i);
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        int rightLength = right(arr, i);
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        max = Math.max(max, leftLength + rightLength + 1);
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      }
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    }
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    return max;
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  }
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  public int left(int[] arr, int i) {
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    int j = i - 1;
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    while (j >= 0 && arr[j] < arr[j + 1]) j--;
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    return i - (j + 1);
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  }
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  public int right(int[] arr, int i) {
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    int j = i + 1;
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    while (j < arr.length && arr[j - 1] > arr[j]) j++;
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    return j - (i + 1);
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  }
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  public boolean isPeak(int[] arr, int i) {
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    return i - 1 >= 0 && i + 1 < arr.length && arr[i - 1] < arr[i] && arr[i + 1] < arr[i];
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  }
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}