典型的近似子串问题!
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
给你左右两个字符串,判断左侧子串是否可以由右侧字符串中抽取部分字符得到(右侧字符串每个字母仅可用一次),全都是小写字母。
思路:建立数组存储每个字母出现的次数
public boolean canConstruct(String ransomNote, String magazine) { int[] letter = new int[26]; for(int i=0;i<magazine.length();i++) letter[magazine.charAt(i)-'a']++; for(int i=0;i<ransomNote.length();i++) letter[ransomNote.charAt(i)-'a']--; for(int i=0;i<26;i++) if(letter[i]<0) return false; return true; }新闻热点
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