682. 棒球比赛

Author: w2xi

Diff for: README.md

@@ -118,6 +118,7 @@
 |637|[二叉树的层平均值](https://leetcode.cn/problems/average-of-levels-in-binary-tree/)|[JavaScript](./algorithms/average-of-levels-in-binary-tree.js)|Easy|
 |645|[错误的集合](https://leetcode.cn/problems/set-mismatch/)|[JavaScript](./algorithms/set-mismatch.js)|Easy|
 |657|[机器人能否返回原点](https://leetcode.cn/problems/robot-return-to-origin/)|[JavaScript](./algorithms/robot-return-to-origin.js)|Easy|
+|682|[棒球比赛](https://leetcode.cn/problems/baseball-game/)|[JavaScript](./algorithms/baseball-game.js)|Easy|
 |687|[最长同值路径](https://leetcode.cn/problems/longest-univalue-path/)|[JavaScript](./algorithms/longest-univalue-path.js)|Medium|
 |700|[二叉搜索树中的搜索](https://leetcode.cn/problems/search-in-a-binary-search-tree/)|[JavaScript](./algorithms/search-in-a-binary-search-tree.js)|Easy|
 |704|[二分查找](https://leetcode.cn/problems/binary-search/)|[JavaScript](./algorithms/binary-search.js)|Easy|

Diff for: algorithms/baseball-game.js

@@ -0,0 +1,21 @@
+/**
+ * @param {string[]} ops
+ * @return {number}
+ */
+var calPoints = function (ops) {
+  const stack = [];
+
+  for (let s of ops) {
+    if (+s === +s) {
+      stack.push(s);
+    } else if (s === "C") {
+      stack.pop();
+    } else if (s === "D") {
+      stack.push(stack.at(-1) * 2);
+    } else if (s === "+") {
+      stack.push(Number(stack.at(-1)) + Number(stack.at(-2)));
+    }
+  }
+
+  return stack.reduce((a, b) => Number(a) + Number(b), 0);
+};