LeetCode_383. Ransom Note

Posted 2020-11-23 邓戈麟

 

383. Ransom Note

Easy

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

 

package leetcode.easy;

public class RansomNote {
	public 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) {
				arr[ransomNote.charAt(i) - ‘a‘]--;
			} else {
				return false;
			}
		}
		return true;
	}

	@org.junit.Test
	public void test() {
		System.out.println(canConstruct("a", "b"));
		System.out.println(canConstruct("aa", "ab"));
		System.out.println(canConstruct("aa", "aab"));
	}
}