Student_Attendance_Record_I.md

551. Student Attendance Record I

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

• 'A' : Absent.
• 'L' : Late.
• '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

Method:

class Solution(object):
    def checkRecord(self, s):
        """
        :type s: str
        :rtype: bool
        """
        for i in range(len(s)-2):
            if s[i]==s[i+1]==s[i+2]=='L':
                return False
        if s.count('A')>1:
            return False
        return True

复杂版：

class Solution(object):
    def checkRecord(self, s):
        """
        :type s: str
        :rtype: bool
        """
        a_count, l_count=0, 0
        for i in s:
            if i=='A':
                a_count+=1
            if a_count>1:
                return False
            if i=='L':
                l_count+=1
            else:
                l_count=0
            if l_count==3:
                return False
        return True

Solution:

class Solution(object):
    def checkRecord(self, s):
        """
        :type s: str
        :rtype: bool
        """
        return s.count('A')<=1 and 'LLL' not in s