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.

樣例

Example 1:

Input: "PPALLP"
Output: True

Example 2:

Input: "PPALLL"
Output: False

輸入測試資料 (每行一個引數)

解題思路1：

直接遍歷即可。

public class Solution {
    /**
     * @param s: a string
     * @return: whether the student could be rewarded according to his attendance record
     */
    public boolean checkRecord(String s) {
        // Write your code here
        int cntA = 0, cntL = 0;
        char[] ss = s.toCharArray();
        
        for(char c : ss){
            if(c == 'A'){
                ++cntA;
                cntL = 0;
            }else if(c == 'L')
                ++cntL;
            else
                cntL = 0;
            
            if(cntA>1 || cntL>2)
                return false;
        }
        
        return true;
    }
}
 

解題思路2：

使用字串匹配函式。

public class Solution {
    /**
     * @param s: a string
     * @return: whether the student could be rewarded according to his attendance record
     */
    public boolean checkRecord(String s) {
        // Write your code here
        return s.indexOf('A') == s.lastIndexOf('A') && !s.contains("LLL");
    }
}