feat(chapter_dynamic_programming): Add js and ts codes for chapter 14.1 (#658)

* feat(chapter_dynamic_programming): Add js and ts codes for chapter 14.1

* style(chapter_dynamic_programming): format code

* refactor(chapter_dynamic_programming): remove main definition and add type

codes/javascript/chapter_dynamic_programming/climbing_stairs_dfs_mem.js

@@ -0,0 +1,30 @@
+/**
+ * File: climbing_stairs_dfs_mem.js
+ * Created Time: 2023-07-26
+ * Author: yuan0221 (yl1452491917@gmail.com)
+ */
+
+/* 记忆化搜索 */
+function dfs(i, mem) {
+    // 已知 dp[1] 和 dp[2] ，返回之
+    if (i == 1 || i == 2) return i;
+    // 若存在记录 dp[i] ，则直接返回之
+    if (mem[i] != -1) return mem[i];
+    // dp[i] = dp[i-1] + dp[i-2]
+    const count = dfs(i - 1, mem) + dfs(i - 2, mem);
+    // 记录 dp[i]
+    mem[i] = count;
+    return count;
+}
+
+/* 爬楼梯：记忆化搜索 */
+function climbingStairsDFSMem(n) {
+    // mem[i] 记录爬到第 i 阶的方案总数，-1 代表无记录
+    const mem = new Array(n + 1).fill(-1);
+    return dfs(n, mem);
+}
+
+/* Driver Code */
+const n = 9;
+const res = climbingStairsDFSMem(n);
+console.log(`爬 ${n} 阶楼梯共有 ${res} 种方案`);