383. Ransom Note

https://leetcode.com/problems/ransom-note/

JavaScript

/**
 * @param {string} ransomNote
 * @param {string} magazine
 * @return {boolean}
 */
var canConstruct = function(ransomNote, magazine) {
    const map = {}
    magazine.split('').forEach(c => {
        map[c] = (map[c] || 0) + 1
    })

    for (let c of ransomNote) {
        if (!map[c]) {
            return false
        }
        map[c]--
    }

    return true
}

Python

class Solution:
    def canConstruct(self, ransomNote, magazine):
        """
        :type ransomNote: str
        :type magazine: str
        :rtype: bool
        """
        lookup = {}
        for c in magazine:
            lookup[c] = lookup.get(c, 0) + 1

        for c in ransomNote:
            if not lookup.get(c):
                return False
            lookup[c] -= 1
        return True

    def canConstruct2(self, ransomNote, magazine):
        """
        :type ransomNote: str
        :type magazine: str
        :rtype: bool
        """
        for c in set(ransomNote):
            if ransomNote.count(c) > magazine.count(c):
                return False
        return True