999. Available Captures for Rook LeetCode Solution
In this guide, you will get 999. Available Captures for Rook LeetCode Solution with the best time and space complexity. The solution to Available Captures for Rook problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.
You are given an 8 x 8 matrix representing a chessboard. There is exactly one white rook represented by ‘R’, some number of white bishops ‘B’, and some number of black pawns ‘p’. Empty squares are represented by ‘.’.
A rook can move any number of squares horizontally or vertically (up, down, left, right) until it reaches another piece or the edge of the board. A rook is attacking a pawn if it can move to the pawn’s square in one move.
Note: A rook cannot move through other pieces, such as bishops or pawns. This means a rook cannot attack a pawn if there is another piece blocking the path.
Return the number of pawns the white rook is attacking.
Example 1:
Input: board = [[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”p”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”R”,”.”,”.”,”.”,”p”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”p”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”]]
Output: 3
Explanation:
In this example, the rook is attacking all the pawns.
Example 2:
Input: board = [[“.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”p”,”p”,”p”,”p”,”p”,”.”,”.”],[“.”,”p”,”p”,”B”,”p”,”p”,”.”,”.”],[“.”,”p”,”B”,”R”,”B”,”p”,”.”,”.”],[“.”,”p”,”p”,”B”,”p”,”p”,”.”,”.”],[“.”,”p”,”p”,”p”,”p”,”p”,”.”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”]]
Output: 0
Explanation:
The bishops are blocking the rook from attacking any of the pawns.
Input: board = [[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”p”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”p”,”.”,”.”,”.”,”.”],[“p”,”p”,”.”,”R”,”.”,”p”,”B”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”B”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”p”,”.”,”.”,”.”,”.”],[“.”,”.”,”.”,”.”,”.”,”.”,”.”,”.”]]
Output: 3
Explanation:
The rook is attacking the pawns at positions b5, d6, and f5.
Constraints:
board.length == 8
board[i].length == 8
board[i][j] is either ‘R’, ‘.’, ‘B’, or ‘p’
There is exactly one cell with board[i][j] == ‘R’
Complexity Analysis
Time Complexity:
Space Complexity:
999. Available Captures for Rook LeetCode Solution in C++
class Solution {
public:
int numRookCaptures(vector<vector<char>>& board) {
int ans = 0;
int i0 = 0;
int j0 = 0;
for (int i = 0; i < 8; ++i)
for (int j = 0; j < 8; ++j)
if (board[i][j] == 'R') {
i0 = i;
j0 = j;
}
for (const vector<int>& d :
vector<vector<int>>({{1, 0}, {0, 1}, {-1, 0}, {0, -1}}))
for (int i = i0 + d[0], j = j0 + d[1]; 0 <= i && i < 8 && 0 <= j && j < 8;
i += d[0], j += d[1]) {
if (board[i][j] == 'p')
++ans;
if (board[i][j] != '.')
break;
}
return ans;
}
}; /* code provided by PROGIEZ */
999. Available Captures for Rook LeetCode Solution in Java
class Solution {
public int numRookCaptures(char[][] board) {
int ans = 0;
int i0 = 0;
int j0 = 0;
for (int i = 0; i < 8; ++i)
for (int j = 0; j < 8; ++j)
if (board[i][j] == 'R') {
i0 = i;
j0 = j;
}
for (int[] d : new int[][] {{1, 0}, {0, 1}, {-1, 0}, {0, -1}})
for (int i = i0 + d[0], j = j0 + d[1]; 0 <= i && i < 8 && 0 <= j && j < 8;
i += d[0], j += d[1]) {
if (board[i][j] == 'p')
++ans;
if (board[i][j] != '.')
break;
}
return ans;
}
} // code provided by PROGIEZ
999. Available Captures for Rook LeetCode Solution in Python
class Solution:
def numRookCaptures(self, board: list[list[str]]) -> int:
ans = 0
for i in range(8):
for j in range(8):
if board[i][j] == 'R':
i0 = i
j0 = j
for d in [[1, 0], [0, 1], [-1, 0], [0, -1]]:
i = i0 + d[0]
j = j0 + d[1]
while 0 <= i < 8 and 0 <= j < 8:
if board[i][j] == 'p':
ans += 1
if board[i][j] != '.':
break
i += d[0]
j += d[1]
return ans # code by PROGIEZ
