Add solution #348

Author: JoshCrozier

README.md

@@ -336,6 +336,7 @@
 345|[Reverse Vowels of a String](./solutions/0345-reverse-vowels-of-a-string.js)|Easy|
 346|[Moving Average from Data Stream](./solutions/0346-moving-average-from-data-stream.js)|Easy|
 347|[Top K Frequent Elements](./solutions/0347-top-k-frequent-elements.js)|Medium|
+348|[Design Tic-Tac-Toe](./solutions/0348-design-tic-tac-toe.js)|Medium|
 349|[Intersection of Two Arrays](./solutions/0349-intersection-of-two-arrays.js)|Easy|
 350|[Intersection of Two Arrays II](./solutions/0350-intersection-of-two-arrays-ii.js)|Easy|
 352|[Data Stream as Disjoint Intervals](./solutions/0352-data-stream-as-disjoint-intervals.js)|Hard|

solutions/0348-design-tic-tac-toe.js

@@ -0,0 +1,59 @@
+/**
+ * 348. Design Tic-Tac-Toe
+ * https://leetcode.com/problems/design-tic-tac-toe/
+ * Difficulty: Medium
+ *
+ * Assume the following rules are for the tic-tac-toe game on an n x n board between two players:
+ * 1. A move is guaranteed to be valid and is placed on an empty block.
+ * 2. Once a winning condition is reached, no more moves are allowed.
+ * 3. A player who succeeds in placing n of their marks in a horizontal, vertical, or diagonal
+ *    row wins the game.
+ *
+ * Implement the TicTacToe class:
+ * - TicTacToe(int n) Initializes the object the size of the board n.
+ * - int move(int row, int col, int player) Indicates that the player with id player plays at the
+ *   cell (row, col) of the board. The move is guaranteed to be a valid move, and the two players
+ *   alternate in making moves. Return
+ *   - 0 if there is no winner after the move,
+ *   - 1 if player 1 is the winner after the move, or
+ *   - 2 if player 2 is the winner after the move.
+ */
+
+/**
+ * @param {number} n
+ */
+var TicTacToe = function(n) {
+  this.size = n;
+  this.rows = new Array(n).fill(0);
+  this.cols = new Array(n).fill(0);
+  this.diagonal = 0;
+  this.antiDiagonal = 0;
+};
+
+/**
+ * @param {number} row
+ * @param {number} col
+ * @param {number} player
+ * @return {number}
+ */
+TicTacToe.prototype.move = function(row, col, player) {
+  const value = player === 1 ? 1 : -1;
+
+  this.rows[row] += value;
+  this.cols[col] += value;
+
+  if (row === col) {
+    this.diagonal += value;
+  }
+
+  if (row + col === this.size - 1) {
+    this.antiDiagonal += value;
+  }
+
+  if (Math.abs(this.rows[row]) === this.size || Math.abs(this.cols[col]) === this.size
+    || Math.abs(this.diagonal) === this.size || Math.abs(this.antiDiagonal) === this.size) {
+    return player;
+  }
+
+  return 0;
+};