LeetCode solutions

2779. Number of Adjacent Elements With the Same Color

My accepted Python solution to LeetCode problem 2779, Number of Adjacent Elements With the Same Color, running in 67ms.

  • Difficulty: Medium
  • Python
  • Runtime 67ms
  • Memory 46.5MB

Read the problem on LeetCode View on GitHub

Python

Accepted on LeetCode — runtime 67ms, memory 46.5MB, accepted 2025-12-31.

python
class Solution:
    def colorTheArray(self, n: int, queries: List[List[int]]) -> List[int]:
        colors = [0] * n
        count = 0
        result = []
        
        for index, color in queries:
            old_color = colors[index]
            
            # Remove old contribution
            if old_color != 0:
                if index > 0 and colors[index - 1] == old_color:
                    count -= 1
                if index < n - 1 and colors[index + 1] == old_color:
                    count -= 1
            
            # Update color
            colors[index] = color
            
            # Add new contribution
            if index > 0 and colors[index - 1] == color:
                count += 1
            if index < n - 1 and colors[index + 1] == color:
                count += 1
            
            result.append(count)
        
        return result

Source