383. Ransom Note

Question

Given two strings ransomNote and magazine, return true* if ransomNote can be constructed by using the letters from magazine and false otherwise*.

Each letter in magazine can only be used once in ransomNote.

Solution

数组统计，统计magazine内的字符。
遍历ransomNote，如果对字符数组位置为0则返回false。
每次遍历减少数组统计结果。

最后返回true。

Code

class Solution {
    public boolean canConstruct(String ransomNote, String magazine) {
        char[] bin = new char[26];
        
        for(char c : magazine.toCharArray()) bin[c-'a']++;
        for(char c : ransomNote.toCharArray()){
            if(bin[c-'a'] == 0) return false;
            bin[c-'a']--;
        }
        
        return true;
    }
}