Ransom Note(leetcode383)

Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it will return false.

Each letter in the magazine string can only be used once in your ransom note.

Note:
You may assume that both strings contain only lowercase letters.

canConstruct("a", "b") -> false
canConstruct("aa", "ab") -> false
canConstruct("aa", "aab") -> true

 

//原來這道題是這個意思(沒有好好理解題意，走了冤枉路) 用map處理也是同樣的
public static boolean canConstruct(String ransomNote, String magazine) {

    int[] arr = new int[26];
    for (int i = 0; i < magazine.length(); i++) {
        arr[magazine.charAt(i) - 'a']++;
    }
    for (int i = 0; i < ransomNote.length(); i++) {
        if(--arr[ransomNote.charAt(i)-'a'] < 0) {
            return false;
        }
    }
    return true;
}