1812. Determine Color of a Chessboard Square
Description
You are given coordinates
, a string that represents the coordinates of a square of the chessboard. Below is a chessboard for your reference.
Return true
if the square is white, and false
if the square is black.
The coordinate will always represent a valid chessboard square. The coordinate will always have the letter first, and the number second.
Example 1:
Input: coordinates = "a1" Output: false Explanation: From the chessboard above, the square with coordinates "a1" is black, so return false.
Example 2:
Input: coordinates = "h3" Output: true Explanation: From the chessboard above, the square with coordinates "h3" is white, so return true.
Example 3:
Input: coordinates = "c7" Output: false
Constraints:
coordinates.length == 2
'a' <= coordinates[0] <= 'h'
'1' <= coordinates[1] <= '8'
Solutions
Solution 1: Find the Pattern
By observing the chessboard, we find that two squares $(x_1, y_1)$ and $(x_2, y_2)$ with the same color satisfy that both $x_1 + y_1$ and $x_2 + y_2$ are either odd or even.
Therefore, we can get the corresponding coordinates $(x, y)$ from coordinates
. If $x + y$ is odd, then the square is white, return true
, otherwise return false
.
The time complexity is $O(1)$, and the space complexity is $O(1)$.
1 2 3 |
|
1 2 3 4 5 |
|
1 2 3 4 5 6 |
|
1 2 3 |
|
1 2 3 |
|
1 2 3 4 5 6 |
|
1 2 3 4 5 6 7 8 9 |
|
1 2 3 |
|