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 "
class Solution {
public String tictactoe(int[][] moves) {
String[][] ab_moves = new String[3][3];
int acounter = 0;
int bcounter = 0;
String result = null;
for(int i=0;i<moves.length;i++){
int row = moves[i][0];
int col = moves[i][1];
if(i%2 == 0){
acounter++;
ab_moves[row][col] = "A";
if(acounter >= 3) result = validateGame(ab_moves,row,col,"A");
}
else{
bcounter++;
ab_moves[row][col] = "B";
if(bcounter >= 3) result = validateGame(ab_moves,row,col,"B");
}
if(result != null) return result;
}
if(result == null && moves.length == 9) result = "Draw";
else result = "Pending";
return result;
}
public String validateGame(String[][] ab_moves, int row, int col, String identifier){
String result = null;
if((row == 0 && col == 0) || (row == 2 && col == 0) || (row == 0 && col == 2) || (row == 2 && col == 2) || (row ==1 && col == 1)){
if(identifier.equals(ab_moves[0][0]) && identifier.equals(ab_moves[1][1]) && identifier.equals(ab_moves[2][2])) result = identifier;
else if(identifier.equals(ab_moves[0][2]) && identifier.equals(ab_moves[1][1]) && identifier.equals(ab_moves[2][0])) result = identifier;
else result = null;
}
if(result == null){
for(int i=0;i<3;i++){
if(identifier.equals(ab_moves[row][i])) result = identifier;
else{
result = null;
break;
}
}
if(result == null){
for(int i=0;i<3;i++){
if(identifier.equals(ab_moves[i][col])) result = identifier;
else{
result = null;
break;
}
}
}
}
return result;
}
}