Problem 3274 Check if Two Chessboard Squares Have the Same Color
Table of Contents
Problem Statement
Link - Problem 3274
Question
You are given two strings, coordinate1 and coordinate2, representing the coordinates of a square on an 8 x 8 chessboard.
Below is the chessboard for reference.
Return true if these two squares have the same color and false otherwise.
The coordinate will always represent a valid chessboard square. The coordinate will always have the letter first (indicating its column), and the number second (indicating its row).
Example 1
Input: coordinate1 = "a1", coordinate2 = "c3"
Output: true
Explanation:
Both squares are black.
Example 2
Input: coordinate1 = "a1", coordinate2 = "h3"
Output: false
Explanation:
Square "a1" is black and "h3" is white.
Constraints
- `coordinate1.length == coordinate2.length == 2`
- `'a' <= coordinate1[0], coordinate2[0] <= 'h'`
- `'1' <= coordinate1[1], coordinate2[1] <= '8'`
Solution
class Solution {
public:
bool checkTwoChessboards(string c1, string c2) {
int col1 = (c1[0] - 'a' + 1 + c1[1] - '0') % 2;
int col2 = (c2[0] - 'a' + 1 + c2[1] - '0') % 2;
return col1 == col2;
}
};
Complexity Analysis
| Algorithm | Time Complexity | Space Complexity |
| ---------- | --------------- | ---------------- |
| Simulation | O(1) | O(1) |
Explanation
1. Intuition
- From the board we can see that `a,c,e,g` are black and `b,d,f,h` are white.
- Similarly `1,3,5,7` are black and `2,4,6,8` are white.
- If we assign black as `0` and white as `1`
then we can see that the sum of the column and row is `even` for black and `odd` for white.
- So given each cordinate, convert it into integer and then find remiander when divided by `2`.
- Then we need to compare the remainder of both the cordinates.
2. Implementation
- A cordinate is given in the form of `a1` where `a` is the column and `1` is the row.
- We need to convert the column and row into integer.
- intger value is calculated as `(column value+1) + row value`.
- Then we find the remainder when divided by `2`.
- We then compare the remainder of both the cordinates.
- Return `true` if both the remainders are same and `false` otherwise.