#LeetCode: Ransom Note

Also Check: Solutions Of May LeetCoding Challenge (2020)

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

Algorithm
1). If the ransomNote is null, return true.
2). If magazine is null return false.
3). If length of magazine should be always equal to or greater than ransomNote note. If its less return false.
4). Now we will convert the magazine into a charArray. And we will create another array charCount which will contain character wise count.
5). We will start iterating the charArray, and increase the count in charCount depending on the character. e.g if the char is 'a', c-'a' will return 0 and the count at the 1th position will be incremented. If the char is y, c-'y' will return 25 and the count at the 25th position will be incremented.
6). Now we will reused the same charArray and convert the ransomNote into array and store in charArray.
7). We will start iterating charArray, check if the charCount is greater than 0 or not for that particular char, if yes decrement the count. Else return false.

GIT URL: Java Solution of Leet Code's Ransom Note problem

Java Solution:

ALSO CHECK: Other LeetCode Solutions in Java

-K Himaanshu Shuklaa..