valid-anagram

Author: taewanseoul

valid-anagram/taewanseoul.ts

@@ -0,0 +1,36 @@
+/**
+ * 242. Valid Anagram
+ * Given two strings s and t, return true if t is an anagram of s, and false otherwise.
+ *
+ * https://leetcode.com/problems/valid-anagram/description/
+ */
+function isAnagram(s: string, t: string): boolean {
+  if (s.length !== t.length) {
+    return false;
+  }
+
+  const charMap = new Map<string, number>();
+
+  for (const char of s) {
+    const count = charMap.get(char);
+    if (count) {
+      charMap.set(char, count + 1);
+    } else {
+      charMap.set(char, 1);
+    }
+  }
+
+  for (const char of t) {
+    const count = charMap.get(char);
+    if (count) {
+      charMap.set(char, count - 1);
+    } else {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// O(n) time
+// O(n) space