Count Values With Equally Spaced Occurrences I - Video Solutions
LeetCode 4048: Count Values With Equally Spaced Occurrences I | Easy HashMap Solution!
Count Values With Equally Spaced Occurrences I - Video Solution
Watch 2 video solutions for Count Values With Equally Spaced Occurrences I, a easy level problem. This walkthrough by engfootsteps has 13 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Problem Statement
You are given an integer array nums.
An integer x is called special if:
xappears exactly three times innums.- All three occurrences of
xare equally spaced innums. In other words, if all occurrences ofxare at indicesi1 < i2 < i3, theni2 - i1 = i3 - i2.
Return the number of distinct special integers in nums.
Example 1:
Input: nums = [1,8,1,5,1,5,8,5]
Output: 2
Explanation:
- 1 is special because it occurs exactly three times at equally spaced indices 0, 2, and 4.
- 5 is special because it occurs exactly three times at equally spaced indices 3, 5, and 7.
- 8 is not special because it occurs only twice.
Therefore, the answer is 2.
Example 2:
Input: nums = [8,8,8,8]
Output: 0
Explanation:
8 is not special because it does not occur exactly three times. Therefore, the answer is 0.
Example 3:
Input: nums = [8,6,6,8,8]
Output: 0
Explanation:
8 occurs at indices 0, 3, and 4, which are not equally spaced. 6 occurs only twice. Therefore, no integer is special.
Constraints:
3 <= nums.length <= 1001 <= nums[i] <= 100