Problem
Use a board whose top-left square is white. Rows and columns start at 0 at the top left. Adjacent squares alternate colors. Return empty text for a position outside the board.
Implement chess_square_color(column, row).
Input
column: The column, counted from the left starting at 0.
row: The row, counted from the top starting at 0.
Output
Return white, black, or an empty string for invalid coordinates.
Constraints
−10 ≤ column, row ≤ 20. Valid board coordinates are 0 through 7.
Examples
Input:
row = 3
column = 2
Expected output:
expected = "black"Input:
long long row = 3;
long long column = 2;
Expected output:
std::string expected = "black";Input:
long row = 3;
long column = 2;
Expected output:
string expected = "black";Explanation
Five steps from the white corner change color an odd number of times.
Input:
row = 0
column = 8
Expected output:
expected = ""Input:
long long row = 0;
long long column = 8;
Expected output:
std::string expected = "";Input:
long row = 0;
long column = 8;
Expected output:
string expected = "";Explanation
Column 8 is outside the valid range 0 through 7.
How to approach it
Try on your own first, then open one hint at a time.
Hint 1
Square color alternates with moves across rows and columns, so only the coordinate pattern matters.
Hint 2
A parity check on row and column can tell you which color to return.
Hint 3
Return empty text immediately when either coordinate is outside the 0 to 7 board range.
Expected complexity
O(1) time, O(1) extra space
References
This challenge is adapted for CodeUtility. Follow the statement and constraints above.