Add solution #649

Author: JoshCrozier

0649-dota2-senate.js

@@ -0,0 +1,53 @@
+/**
+ * 649. Dota2 Senate
+ * https://leetcode.com/problems/dota2-senate/
+ * Difficulty: Medium
+ *
+ * In the world of Dota2, there are two parties: the Radiant and the Dire.
+ *
+ * The Dota2 senate consists of senators coming from two parties. Now the Senate wants
+ * to decide on a change in the Dota2 game. The voting for this change is a round-based
+ * procedure. In each round, each senator can exercise one of the two rights:
+ * - Ban one senator's right: A senator can make another senator lose all his rights in
+ *   this and all the following rounds.
+ * - Announce the victory: If this senator found the senators who still have rights to
+ *   vote are all from the same party, he can announce the victory and decide on the
+ *   change in the game.
+ *
+ * Given a string senate representing each senator's party belonging. The character 'R'
+ * and 'D' represent the Radiant party and the Dire party. Then if there are n senators,
+ * the size of the given string will be n.
+ *
+ * The round-based procedure starts from the first senator to the last senator in the
+ * given order. This procedure will last until the end of voting. All the senators who
+ * have lost their rights will be skipped during the procedure.
+ *
+ * Suppose every senator is smart enough and will play the best strategy for his own
+ * party. Predict which party will finally announce the victory and change the Dota2
+ * game. The output should be "Radiant" or "Dire".
+*/
+
+/**
+ * @param {string} senate
+ * @return {string}
+ */
+var predictPartyVictory = function(senate) {
+  const rQueue = [];
+  const dQueue = [];
+
+  for (let i = 0; i < senate.length; i++) {
+    if (senate[i] === 'R') rQueue.push(i);
+    else dQueue.push(i);
+  }
+
+  while (rQueue.length && dQueue.length) {
+    const [rIndex, dIndex] = [rQueue.shift(), dQueue.shift()];
+    if (rIndex < dIndex) {
+      rQueue.push(rIndex + senate.length);
+    } else {
+      dQueue.push(dIndex + senate.length);
+    }
+  }
+
+  return rQueue.length > 0 ? 'Radiant' : 'Dire';
+};

README.md

@@ -222,6 +222,7 @@
 643|[Maximum Average Subarray I](./0643-maximum-average-subarray-i.js)|Easy|
 645|[Set Mismatch](./0645-set-mismatch.js)|Medium|
 648|[Replace Words](./0648-replace-words.js)|Medium|
+649|[Dota2 Senate](./0649-dota2-senate.js)|Medium|
 653|[Two Sum IV - Input is a BST](./0653-two-sum-iv-input-is-a-bst.js)|Easy|
 680|[Valid Palindrome II](./0680-valid-palindrome-ii.js)|Easy|
 686|[Repeated String Match](./0686-repeated-string-match.js)|Easy|