feat: add typescript solution to lc problem: No.0171.Excel Sheet Column Number (doocs#438)

Author: zhaocchen

solution/0100-0199/0171.Excel Sheet Column Number/README.md

@@ -76,6 +76,18 @@ class Solution {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function titleToNumber(columnTitle: string): number {
+    let res: number = 0;
+    for (let char of columnTitle) {
+        res = res * 26 + char.charCodeAt(0) - 64;
+    }
+    return res;
+};
+```
+
 ### **C++**
 
 ```cpp

solution/0100-0199/0171.Excel Sheet Column Number/README_EN.md

@@ -87,6 +87,18 @@ class Solution {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function titleToNumber(columnTitle: string): number {
+    let res: number = 0;
+    for (let char of columnTitle) {
+        res = res * 26 + char.charCodeAt(0) - 64;
+    }
+    return res;
+};
+```
+
 ### **C++**
 
 ```cpp

solution/0100-0199/0171.Excel Sheet Column Number/Solution.ts

@@ -0,0 +1,7 @@
+function titleToNumber(columnTitle: string): number {
+    let res: number = 0;
+    for (let char of columnTitle) {
+        res = res * 26 + char.charCodeAt(0) - 64;
+    }
+    return res;
+};