update

Author: liuhanqu

.prettierrc

@@ -0,0 +1,10 @@
+{
+  "printWidth": 100,
+  "tabWidth": 2,
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": true,
+  "jsxBracketSameLine": true,
+  "bracketSpacing": true,
+  "trailingComma": "es5"
+}

README.md

@@ -15,6 +15,7 @@ LeetCode Problems' Solutions in JavaScript
 9.  [第一个错误的版本](./algorithms/easy/solution/solution.js)
 10. [两个数组的交集 II](./algorithms/easy/intersect/intersect.js)
 11. [汉明距离](./algorithms/easy/hammingDistance/hammingDistance.js)
+12. [汉明距离](./algorithms/easy/isValid/isValid.js)
 
 ## medium
 

algorithms/easy/isValid/isValid.js

@@ -0,0 +1,27 @@
+// description: https://leetcode-cn.com/explore/interview/card/top-interview-questions-easy/26/others/68/
+// 有效的括号
+
+var isValid = function(s) {
+  const charMap = {
+    ')': '(',
+    ']': '[',
+    '}': '{',
+  };
+
+  const leftChars = ['(', '[', '{'];
+
+  const stash = [];
+
+  for (const char of s) {
+    if (leftChars.indexOf(char) !== -1) {
+      stash.push(char);
+      continue;
+    }
+    const leftChar = charMap[char];
+    if (leftChar !== stash[stash.length - 1]) {
+      return false;
+    }
+    stash.pop();
+  }
+  return stash.length === 0;
+};