content: package codingquestions.leetcode;
  
  /*
  2210. Count Hills and Valleys in an Array
  Solved
  Easy
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  Hint
  You are given a 0-indexed integer array nums. An index i is part of a hill in nums if the closest non-equal neighbors of i are smaller than nums[i]. Similarly, an index i is part of a valley in nums if the closest non-equal neighbors of i are larger than nums[i]. Adjacent indices i and j are part of the same hill or valley if nums[i] == nums[j].
  
  Note that for an index to be part of a hill or valley, it must have a non-equal neighbor on both the left and right of the index.
  
  Return the number of hills and valleys in nums.
  
   
  
  Example 1:
  
  Input: nums = [2,4,1,1,6,5]
  Output: 3
  Explanation:
  At index 0: There is no non-equal neighbor of 2 on the left, so index 0 is neither a hill nor a valley.
  At index 1: The closest non-equal neighbors of 4 are 2 and 1. Since 4 > 2 and 4 > 1, index 1 is a hill. 
  At index 2: The closest non-equal neighbors of 1 are 4 and 6. Since 1 < 4 and 1 < 6, index 2 is a valley.
  At index 3: The closest non-equal neighbors of 1 are 4 and 6. Since 1 < 4 and 1 < 6, index 3 is a valley, but note that it is part of the same valley as index 2.
  At index 4: The closest non-equal neighbors of 6 are 1 and 5. Since 6 > 1 and 6 > 5, index 4 is a hill.
  At index 5: There is no non-equal neighbor of 5 on the right, so index 5 is neither a hill nor a valley. 
  There are 3 hills and valleys so we return 3.
  Example 2:
  
  Input: nums = [6,6,5,5,4,1]
  Output: 0
  Explanation:
  At index 0: There is no non-equal neighbor of 6 on the left, so index 0 is neither a hill nor a valley.
  At index 1: There is no non-equal neighbor of 6 on the left, so index 1 is neither a hill nor a valley.
  At index 2: The closest non-equal neighbors of 5 are 6 and 4. Since 5 < 6 and 5 > 4, index 2 is neither a hill nor a valley.
  At index 3: The closest non-equal neighbors of 5 are 6 and 4. Since 5 < 6 and 5 > 4, index 3 is neither a hill nor a valley.
  At index 4: The closest non-equal neighbors of 4 are 5 and 1. Since 4 < 5 and 4 > 1, index 4 is neither a hill nor a valley.
  At index 5: There is no non-equal neighbor of 1 on the right, so index 5 is neither a hill nor a valley.
  There are 0 hills and valleys so we return 0.
   
  
  Constraints:
  
  3 <= nums.length <= 100
  1 <= nums[i] <= 100
  */
  public class CountHillsAndValleysInAnArray {
      public int countHillValley(int[] nums) {
          int res = 0;
          for(int i = 1; i < nums.length - 1; i++){
              if(nums[i] == nums[i - 1])
                  continue;
              
              int l = i - 1, r = i + 1;
              while(l >= 0 && nums[l + 1] == nums[l])
                  l--;
              
              while(r < nums.length && nums[r - 1] == nums[r])
                  r++;
              
              if(l >= 0 && r < nums.length){
                  if((nums[l] < nums[i] && nums[r] < nums[i]) || (nums[l] > nums[i] && nums[r] > nums[i]))
                      res++;
              }
          }
          return res;
      }
  }
  