added ransomNote solution to easy folder

Author: DevDelvo

Easy/ransomNote.js

@@ -0,0 +1,36 @@
+// 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
+
+const canConstruct = function(ransomNote, magazine) {
+    const magazineMap = {};
+    
+    for (const char of magazine) {
+        if (magazineMap[char]) {
+            magazineMap[char]++;
+        } else {
+            magazineMap[char] = 1;
+        }
+    }
+    
+    for (const char of ransomNote) {
+        if (magazineMap[char] > 0) {
+            magazineMap[char]--;
+            continue;
+        }
+        return false;
+    }
+    return true;
+};
+
+console.log(canConstruct("a", "b")) // -> false
+console.log(canConstruct("aa", "ab")) // -> false
+console.log(canConstruct("aa", "aab")) // -> true