#383 - Ransom Note

Easy • View on LeetCode • View on GitHub

Problem Description

Given two stings ransomNote and magazine, return true if ransomNote can be constructed from magazine and false otherwise.

Each letter in magazine can only be used once in ransomNote.

Solution

/**
 * @param {string} ransomNote
 * @param {string} magazine
 * @return {boolean}
 */
var canConstruct = function(ransomNote, magazine) {
  const map = new Map();

  for (let i = magazine.length - 1; i > -1; i--) {
    map.set(magazine[i], (map.get(magazine[i]) || 0) + 1);
  }

  for (let i = ransomNote.length - 1; i > -1; i--) {
    if ((map.get(ransomNote[i]) || 0) < 1) {
      return false;
    }
    map.set(ransomNote[i], map.get(ransomNote[i]) - 1);
  }

  return true;
};