551. 学生出勤记录 I

Author: w2xi

Diff for: README.md

@@ -101,8 +101,9 @@
 |520|[检测大写字母](https://leetcode.cn/problems/detect-capital/)|[JavaScript](./algorithms/detect-capital.js)|Easy|
 |541|[反转字符串 II](https://leetcode.cn/problems/reverse-string-ii/)|[JavaScript](./algorithms/reverse-string-ii.js)|Easy|
 |543|[二叉树的直径](https://leetcode.cn/problems/diameter-of-binary-tree/)|[JavaScript](./algorithms/diameter-of-binary-tree.js)|Easy|
-|566|[重塑矩阵](https://leetcode.cn/problems/reshape-the-matrix/)|[JavaScript](./algorithms/reshape-the-matrix.js)|Easy|
+|551|[学生出勤记录 I](https://leetcode.cn/problems/student-attendance-record-i/)|[JavaScript](./algorithms/student-attendance-record-i.js)|Easy|
 |557|[反转字符串中的单词 III](https://leetcode.cn/problems/reverse-words-in-a-string-iii/)|[JavaScript](./algorithms/reverse-words-in-a-string-iii.js)|Easy|
+|566|[重塑矩阵](https://leetcode.cn/problems/reshape-the-matrix/)|[JavaScript](./algorithms/reshape-the-matrix.js)|Easy|
 |598|[范围求和 II](https://leetcode.cn/problems/range-addition-ii/)|[JavaScript](./algorithms/range-addition-ii.js)|Easy|
 |617|[合并二叉树](https://leetcode.cn/problems/merge-two-binary-trees/)|[JavaScript](./algorithms/merge-two-binary-trees.js)|Easy|
 |628|[三个数的最大乘积](https://leetcode.cn/problems/maximum-product-of-three-numbers/)|[JavaScript](./algorithms/maximum-product-of-three-numbers.js)|Easy|

Diff for: algorithms/student-attendance-record-i.js

@@ -0,0 +1,23 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var checkRecord = function (s) {
+  let absentCount = 0;
+  let currLateCount = 0;
+  let maxLateCount = 0;
+
+  for (let i = 0; i < s.length; i++) {
+    if (s[i] === "A") {
+      absentCount++;
+    }
+    if (s[i] === "L") {
+      currLateCount++;
+      maxLateCount = Math.max(currLateCount, maxLateCount);
+    } else {
+      currLateCount = 0;
+    }
+  }
+
+  return absentCount < 2 && maxLateCount < 3;
+};