feat: add typescript solution to lc problem: No.2243

No.2243.Calculate Digit Sum of a String

Author: zhaocchen

solution/2200-2299/2243.Calculate Digit Sum of a String/README.md

@@ -80,7 +80,18 @@ s 变为 "0" + "0" + "0" = "000" ，其长度等于 k ，所以返回 "000" 。
 ### **TypeScript**
 
 ```ts
-
+function digitSum(s: string, k: number): string {
+    let ans = [];
+    while (s.length > k) {
+        for (let i = 0; i < s.length; i += k) {
+            let cur = s.slice(i, i + k);
+            ans.push(cur.split('').reduce((a, c) => a + parseInt(c), 0));
+        }
+        s = ans.join('');
+        ans = [];
+    }
+    return s;
+};
 ```
 
 ### **...**

solution/2200-2299/2243.Calculate Digit Sum of a String/README_EN.md

@@ -71,7 +71,18 @@ s becomes "0" + "0" + "0" = "000", whose
 ### **TypeScript**
 
 ```ts
-
+function digitSum(s: string, k: number): string {
+    let ans = [];
+    while (s.length > k) {
+        for (let i = 0; i < s.length; i += k) {
+            let cur = s.slice(i, i + k);
+            ans.push(cur.split('').reduce((a, c) => a + parseInt(c), 0));
+        }
+        s = ans.join('');
+        ans = [];
+    }
+    return s;
+};
 ```
 
 ### **...**

solution/2200-2299/2243.Calculate Digit Sum of a String/Solution.ts

@@ -0,0 +1,12 @@
+function digitSum(s: string, k: number): string {
+    let ans = [];
+    while (s.length > k) {
+        for (let i = 0; i < s.length; i += k) {
+            let cur = s.slice(i, i + k);
+            ans.push(cur.split('').reduce((a, c) => a + parseInt(c), 0));
+        }
+        s = ans.join('');
+        ans = [];
+    }
+    return s;
+};