Leetcode551. Student Attendance Record I一趟遍歷

You are given a string representing an attendance record for a student. The record only contains the following three characters:

1. 'A' : Absent.
2. 'L' : Late.
3. 'P' : Present.

A student could be rewarded if his attendance record doesn't contain more than one 'A' (absent) or more than two continuous 'L' (late).

You need to return whether the student could be rewarded according to his attendance record.

Example 1:

Input: "PPALLP"
Output: True

Example 2:

Input: "PPALLL"
Output: False

class Solution {
public:
    bool checkRecord(string s) {
        int na = 0;
        int nl = 0;
        for (int i = 0; i < s.length(); i++)
        {
            if (s[i] == 'A') {
                na++;
            }else if (s[i] == 'L') {
                nl++;
            }
            if (s[i] != 'L') {
                nl = 0;
            }
            if (na > 1 || nl > 2) {
                return false;
            }
        }
        return true;
    }
};