diff --git a/HamSungJun/HashTable/Solution_409.ts b/HamSungJun/HashTable/Solution_409.ts
new file mode 100644
index 0000000..f31819b
--- /dev/null
+++ b/HamSungJun/HashTable/Solution_409.ts
@@ -0,0 +1,21 @@
+function longestPalindrome (s: string): number {
+  const charCountMap = new Map()
+  for (let i = 0; i < s.length; i++) {
+    const nextChar = s[i]
+    if (charCountMap.has(nextChar)) {
+      charCountMap.set(nextChar, charCountMap.get(nextChar) + 1)
+    } else {
+      charCountMap.set(nextChar, 1)
+    }
+  }
+  let sum = 0
+  for (const v of charCountMap.values()) {
+    if (v % 2 === 0) {
+      sum += v
+    } else if (v !== 1) {
+      sum += (v - 1)
+    }
+  }
+  /* 카운트가 1인 알파벳이 있었다면 그중에 하나만 채택해서 마지막 값에 더한다. */
+  return sum === s.length ? sum : sum + 1
+};
diff --git a/HamSungJun/HashTable/Solution_599.ts b/HamSungJun/HashTable/Solution_599.ts
new file mode 100644
index 0000000..ad06522
--- /dev/null
+++ b/HamSungJun/HashTable/Solution_599.ts
@@ -0,0 +1,16 @@
+function findRestaurant (list1: string[], list2: string[]): string[] {
+  const m1 = new Map()
+  const commonList: any[] = []
+  let minIndexSum = Number.MAX_SAFE_INTEGER
+  list1.forEach((v, i) => { m1.set(v, i) })
+  list2.forEach((v, i) => {
+    if (m1.has(v)) {
+      const nextIndexSum = m1.get(v) + i
+      minIndexSum = Math.min(minIndexSum, nextIndexSum)
+      if (minIndexSum === nextIndexSum) {
+        commonList.push([v, nextIndexSum])
+      }
+    }
+  })
+  return commonList.filter(([v, indexSum]) => indexSum === minIndexSum).map(([v, _]) => v)
+};
diff --git a/HamSungJun/HashTable/Solution_953.ts b/HamSungJun/HashTable/Solution_953.ts
new file mode 100644
index 0000000..8c64cfd
--- /dev/null
+++ b/HamSungJun/HashTable/Solution_953.ts
@@ -0,0 +1,32 @@
+function isAlienSorted (words: string[], order: string): boolean {
+  const sortMap = new Map()
+  for (let i = 0; i < order.length; i++) {
+    sortMap.set(order[i], i)
+  }
+  for (let i = 0; i < words.length - 1; i++) {
+    const w1 = words[i]
+    const w2 = words[i + 1]
+    if (isUnsorted(w1, w2, sortMap)) return false
+  }
+  return true
+};
+
+function isUnsorted (w1: string, w2: string, sortMap: Map<string, number>): boolean {
+  const minLength = Math.min(w1.length, w2.length)
+  for (let i = 0; i < minLength; i++) {
+    const weightW1 = sortMap.get(w1[i]) as number
+    const weightW2 = sortMap.get(w2[i]) as number
+    if (weightW1 > weightW2) {
+      return true
+    } else if (weightW1 === weightW2) {
+      if (i === minLength - 1 && w1.length > w2.length) {
+        return true
+      }
+    } else if (weightW1 < weightW2) {
+      return false
+    }
+  }
+  return false
+}
+
+console.log(isAlienSorted(['hello', 'leetcode'], 'hlabcdefgijkmnopqrstuvwxyz'))