package LeetCode_1275 /** * 1275. Find Winner on a Tic Tac Toe Game * https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game/description/ * * 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" 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. * */ class Solution { fun tictactoe(moves: Array<IntArray>): String { val n = 3 val rows = IntArray(n) val cols = IntArray(n) var dia1 = 0 var dia2 = 0 //A is 1 var player = 1 for (move in moves) { val x = move[0] val y = move[1] rows[x] += player cols[y] += player //diagonal from top left to right bottom if (x == y) { dia1 += player } //diagonal from top right to left bottom if (x == n - y - 1) { dia2 += player } //change player every turn player *= -1 } for (i in 0 until n) { if (rows[i] == n || cols[i] == n || dia1 == n || dia2 == n) { return "A" } if (rows[i] == -n || cols[i] == -n || dia1 == -n || dia2 == -n) { return "B" } } if (moves.size < n * n) { return "Pending" } else { return "Drawing" } } }