Leetcode Problem 2237. Count Positions on Street With Required Brightness

2237. Count Positions on Street With Required Brightness

Leetcode Solutions

Prefix Sum and Difference Array Approach

  1. Initialize a difference array brightness of size n + 1 with all zeros.
  2. For each light [position, range] in lights: a. Calculate the start of the range as max(0, position - range). b. Calculate the end of the range as min(n - 1, position + range). c. Increment brightness[start] by 1 to indicate the start of a new range of light. d. Decrement brightness[end + 1] by 1 to indicate the end of the range of light.
  3. Initialize a variable currentBrightness to keep track of the running sum of brightness.
  4. Initialize a counter result to count the number of positions meeting the requirement.
  5. Iterate over the positions from 0 to n - 1: a. Add brightness[i] to currentBrightness to get the brightness at position i. b. If currentBrightness is greater than or equal to requirement[i], increment result.
  6. Return result as the number of positions meeting the requirement.
UML Thumbnail

Brute Force Approach

Ask Question

Programming Language
image/screenshot of info(optional)
Full Screen
Loading...

Suggested Answer

Answer
Full Screen
Copy Answer Code
Loading...