[LeetCode] 551. Student Attendance Record I

轉自LeetCode

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

<Solution>

想法如下

• 去計數Ａ和Ｌ的出現次數即可

code如下

C++

	class Solution {
	public:
	bool checkRecord(string s) {
	int cntA = 0, cntL = 0;
	for(const auto &c : s) {
	if(c == 'A') {
	++cntA;
	cntL = 0;
	}
	else if(c == 'L') {
	++cntL;
	}
	else {
	cntL = 0;
	}
	if(cntA > 1 || cntL > 2) {
	return false;
	}
	}
	return true;
	}
	};

view raw studentAttendance.cpp hosted with ❤ by GitHub

Java

Java 可以使用 regular expression 來解

	class Solution {
	public boolean checkRecord(String s) {
	return !s.matches(".*LLL.*|.*A.*A.*");
	}
	}

view raw studentAttendance.java hosted with ❤ by GitHub