703466. Reducing Walls
Basic
Reducing Walls
Summary
The "Reducing Walls" problem involves reducing a given array of walls to minimize their overall length. The goal is to find the optimal way to merge adjacent walls while maintaining their integrity, ensuring that no two adjacent walls are merged. This problem requires an understanding of arrays and data structures.
Detailed Explanation
To solve this problem, we can iterate through the array of walls and maintain a variable current_wall to keep track of the current wall being processed. For each wall in the array:
- If the current wall is not merged with the previous one (i.e., their lengths are different), increment the
merged_wallscounter. - Update the
current_walllength by adding the length of the current wall to the previous wall's length (if it existed). - Repeat this process until all walls have been processed.
Here's a step-by-step breakdown:
1. Initialize `merged_walls` = 0 and `current_wall` = null
2. Iterate through the array of walls:
- If `current_wall` is null or its length differs from the current wall's length:
- Increment `merged_walls` by 1
- Update `current_wall` to be the sum of the current wall's length and the previous wall's length (if it existed)
- Repeat until all walls have been processed
Time complexity: O(n), where n is the number of walls in the array.
Space complexity: O(1), as we only use a constant amount of space to store merged_walls and current_wall.
Optimized Solutions
Java
public int reduceWalls(int[] walls) {
int mergedWalls = 0;
int currentWall = 0;
for (int wall : walls) {
if (wall != currentWall) {
mergedWalls++;
currentWall = wall;
}
}
return mergedWalls;
}