Ransom Note

Description

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.

 

Example 1:

Input: ransomNote = "a", magazine = "b"
Output: false

Example 2:

Input: ransomNote = "aa", magazine = "ab"
Output: false

Example 3:

Input: ransomNote = "aa", magazine = "aab"
Output: true

 

Constraints:

• You may assume that both strings contain only lowercase letters.

Solution(javascript)

/**
 * @param {string} ransomNote
 * @param {string} magazine
 * @return {boolean}
 */
var canConstruct = function(ransomNote, magazine) {
    const map = {}
    for(let c of magazine) {
        map[c] = (map[c] || 0) + 1
    }
    
    const map2 = {}
    for(let c of ransomNote) {
        map2[c] = (map2[c] || 0) + 1
        if(map2[c] > (map[c] || 0)) {
            return false
        }
    }
    return true
};