Add solution #822

Author: JoshCrozier

README.md

@@ -630,6 +630,7 @@
 819|[Most Common Word](./0819-most-common-word.js)|Easy|
 820|[Short Encoding of Words](./0820-short-encoding-of-words.js)|Medium|
 821|[Shortest Distance to a Character](./0821-shortest-distance-to-a-character.js)|Easy|
+822|[Card Flipping Game](./0822-card-flipping-game.js)|Medium|
 824|[Goat Latin](./0824-goat-latin.js)|Easy|
 827|[Making A Large Island](./0827-making-a-large-island.js)|Hard|
 830|[Positions of Large Groups](./0830-positions-of-large-groups.js)|Easy|

solutions/0822-card-flipping-game.js

@@ -0,0 +1,46 @@
+/**
+ * 822. Card Flipping Game
+ * https://leetcode.com/problems/card-flipping-game/
+ * Difficulty: Medium
+ *
+ * You are given two 0-indexed integer arrays fronts and backs of length n, where the ith card has
+ * the positive integer fronts[i] printed on the front and backs[i] printed on the back. Initially,
+ * each card is placed on a table such that the front number is facing up and the other is facing
+ * down. You may flip over any number of cards (possibly zero).
+ *
+ * After flipping the cards, an integer is considered good if it is facing down on some card and
+ * not facing up on any card.
+ *
+ * Return the minimum possible good integer after flipping the cards. If there are no good integers,
+ * return 0.
+ */
+
+/**
+ * @param {number[]} fronts
+ * @param {number[]} backs
+ * @return {number}
+ */
+var flipgame = function(fronts, backs) {
+  const impossibleValues = new Set();
+  const n = fronts.length;
+
+  for (let i = 0; i < n; i++) {
+    if (fronts[i] === backs[i]) {
+      impossibleValues.add(fronts[i]);
+    }
+  }
+
+  let minGoodValue = Infinity;
+
+  for (let i = 0; i < n; i++) {
+    if (!impossibleValues.has(fronts[i])) {
+      minGoodValue = Math.min(minGoodValue, fronts[i]);
+    }
+
+    if (!impossibleValues.has(backs[i])) {
+      minGoodValue = Math.min(minGoodValue, backs[i]);
+    }
+  }
+
+  return minGoodValue === Infinity ? 0 : minGoodValue;
+};