1275. Find Winner on a Tic Tac Toe Game

Tic-tac-toe is played by two players A and B on a 3 x 3 grid.

Here are the rules of Tic-Tac-Toe:

• Players take turns placing characters into empty squares (" ").
• The first player A always places "X" characters, while the second player B always places "O" characters.
• "X" and "O" characters are always placed into empty squares, never on filled ones.
• The game ends when there are 3 of the same (non-empty) character filling any row, column, or diagonal.
• The game also ends if all squares are non-empty.
• No more moves can be played if the game is over.

Given an array `moves` where each element is another array of size 2 corresponding to the row and column of the grid where they mark their respective character in the order in which A and B play.

Return the winner of the game if it exists (A or B), in case the game ends in a draw return "Draw", if there are still movements to play return "Pending".

You can assume that `moves` is valid (It follows the rules of Tic-Tac-Toe), the grid is initially empty and A will play first.

Example 1:

```Input: moves = [[0,0],[2,0],[1,1],[2,1],[2,2]]
Output: "A"
Explanation: "A" wins, he always plays first.
"X  "    "X  "    "X  "    "X  "    "X  "
"   " -> "   " -> " X " -> " X " -> " X "
"   "    "O  "    "O  "    "OO "    "OOX"
```

Example 2:

```Input: moves = [[0,0],[1,1],[0,1],[0,2],[1,0],[2,0]]
Output: "B"
Explanation: "B" wins.
"X  "    "X  "    "XX "    "XXO"    "XXO"    "XXO"
"   " -> " O " -> " O " -> " O " -> "XO " -> "XO "
"   "    "   "    "   "    "   "    "   "    "O  "
```

Example 3:

```Input: moves = [[0,0],[1,1],[2,0],[1,0],[1,2],[2,1],[0,1],[0,2],[2,2]]
Output: "Draw"
Explanation: The game ends in a draw since there are no moves to make.
"XXO"
"OOX"
"XOX"
```

Example 4:

```Input: moves = [[0,0],[1,1]]
Output: "Pending"
Explanation: The game has not finished yet.
"X  "
" O "
"   "
```

Constraints:

• `1 <= moves.length <= 9`
• `moves[i].length == 2`
• `0 <= moves[i][j] <= 2`
• There are no repeated elements on `moves`.
• `moves` follow the rules of tic tac toe.

1275. Find Winner on a Tic Tac Toe Game
``````struct Solution;

impl Solution {
fn tictactoe(moves: Vec<Vec<i32>>) -> String {
let mut board = [[' '; 3]; 3];
let mut player = 'X';
let n = moves.len();
for m in moves {
let r = m[0] as usize;
let c = m[1] as usize;
board[r][c] = player;
player = if player == 'X' { 'O' } else { 'X' };
}
let ss = [
[(0, 0), (0, 1), (0, 2)],
[(1, 0), (1, 1), (1, 2)],
[(2, 0), (2, 1), (2, 2)],
[(0, 0), (1, 0), (2, 0)],
[(0, 1), (1, 1), (2, 1)],
[(0, 2), (1, 2), (2, 2)],
[(0, 0), (1, 1), (2, 2)],
[(0, 2), (1, 1), (2, 0)],
];
for s in &ss {
let mut a = 0;
let mut b = 0;
for p in s {
let i = p.0;
let j = p.1;
match board[i][j] {
'X' => a += 1,
'O' => b += 1,
_ => {}
}
}
if a == 3 {
return "A".to_string();
}
if b == 3 {
return "B".to_string();
}
}
if n == 9 {
return "Draw".to_string();
}
"Pending".to_string()
}
}

#[test]
fn test() {
let moves = vec_vec_i32![[0, 0], [2, 0], [1, 1], [2, 1], [2, 2]];
let res = "A".to_string();
assert_eq!(Solution::tictactoe(moves), res);
let moves = vec_vec_i32![[0, 0], [1, 1], [0, 1], [0, 2], [1, 0], [2, 0]];
let res = "B".to_string();
assert_eq!(Solution::tictactoe(moves), res);
let moves = vec_vec_i32![
[0, 0],
[1, 1],
[2, 0],
[1, 0],
[1, 2],
[2, 1],
[0, 1],
[0, 2],
[2, 2]
];
let res = "Draw".to_string();
assert_eq!(Solution::tictactoe(moves), res);
let moves = vec_vec_i32![[0, 0], [1, 1]];
let res = "Pending".to_string();
assert_eq!(Solution::tictactoe(moves), res);
}
``````