feat: $771 Jewels and Stones (azl397985856#57)

Author: fxxqq

todo/candidates/771.jewels-and-stones.js

@@ -0,0 +1,18 @@
+/*
+ * @lc app=leetcode id=771 lang=javascript
+ *
+ * [460] LFU Cache
+ */
+/**
+ * @param {string} J
+ * @param {string} S
+ * @return {number}
+ * @description 思路：正则把石头里的宝石replace掉，长度相减，就是结果
+ */
+var numJewelsInStones = function(J, S) {
+  let newS = S
+  for (let i = 0; i < J.length; i++) {
+    newS = newS.replace(new RegExp(J[i], 'g'), '')
+  }
+  return S.length - newS.length
+}