feat: add solutions to lc problems: No.1217,1218

* No.1217.Minimum Cost to Move Chips to The Same Position
* No.1218.Longest Arithmetic Subsequence of Given Difference

Author: yanglbme

solution/1200-1299/1217.Minimum Cost to Move Chips to The Same Position/README.md

@@ -128,6 +128,23 @@ func minCostToMoveChips(position []int) int {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} position
+ * @return {number}
+ */
+var minCostToMoveChips = function (position) {
+    let a = 0;
+    for (let v of position) {
+        a += v % 2;
+    }
+    let b = position.length - a;
+    return Math.min(a, b);
+};
+```
+
 ### **...**
 
 ```

solution/1200-1299/1217.Minimum Cost to Move Chips to The Same Position/README_EN.md

@@ -108,6 +108,23 @@ func minCostToMoveChips(position []int) int {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} position
+ * @return {number}
+ */
+var minCostToMoveChips = function (position) {
+    let a = 0;
+    for (let v of position) {
+        a += v % 2;
+    }
+    let b = position.length - a;
+    return Math.min(a, b);
+};
+```
+
 ### **...**
 
 ```

solution/1200-1299/1217.Minimum Cost to Move Chips to The Same Position/Solution.js

@@ -0,0 +1,12 @@
+/**
+ * @param {number[]} position
+ * @return {number}
+ */
+var minCostToMoveChips = function (position) {
+    let a = 0;
+    for (let v of position) {
+        a += v % 2;
+    }
+    let b = position.length - a;
+    return Math.min(a, b);
+};

solution/1200-1299/1218.Longest Arithmetic Subsequence of Given Difference/README.md

@@ -48,6 +48,10 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+**方法一：动态规划**
+
+时间复杂度 $O(n)$。
+
 <!-- tabs:start -->
 
 ### **Python3**
@@ -119,6 +123,25 @@ func max(a, b int) int {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} arr
+ * @param {number} difference
+ * @return {number}
+ */
+var longestSubsequence = function (arr, difference) {
+    let ans = 1;
+    const dp = new Map();
+    for (const v of arr) {
+        dp.set(v, (dp.get(v - difference) || 0) + 1);
+        ans = Math.max(ans, dp.get(v));
+    }
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/1200-1299/1218.Longest Arithmetic Subsequence of Given Difference/README_EN.md

@@ -109,6 +109,25 @@ func max(a, b int) int {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} arr
+ * @param {number} difference
+ * @return {number}
+ */
+var longestSubsequence = function (arr, difference) {
+    let ans = 1;
+    const dp = new Map();
+    for (const v of arr) {
+        dp.set(v, (dp.get(v - difference) || 0) + 1);
+        ans = Math.max(ans, dp.get(v));
+    }
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/1200-1299/1218.Longest Arithmetic Subsequence of Given Difference/Solution.js

@@ -0,0 +1,14 @@
+/**
+ * @param {number[]} arr
+ * @param {number} difference
+ * @return {number}
+ */
+var longestSubsequence = function (arr, difference) {
+    let ans = 1;
+    const dp = new Map();
+    for (const v of arr) {
+        dp.set(v, (dp.get(v - difference) || 0) + 1);
+        ans = Math.max(ans, dp.get(v));
+    }
+    return ans;
+};