Merge pull request #1193 from xiaofei-2020/back14

添加（0491.递增子序列.md）：增加typescript版本

problems/0491.递增子序列.md

@@ -396,7 +396,35 @@ var findSubsequences = function(nums) {
 
 ```
 
+## TypeScript
+
+```typescript
+function findSubsequences(nums: number[]): number[][] {
+    const resArr: number[][] = [];
+    backTracking(nums, 0, []);
+    return resArr;
+    function backTracking(nums: number[], startIndex: number, route: number[]): void {
+        let length: number = nums.length;
+        if (route.length >= 2) {
+            resArr.push(route.slice());
+        }
+        const usedSet: Set<number> = new Set();
+        for (let i = startIndex; i < length; i++) {
+            if (
+                nums[i] < route[route.length - 1] ||
+                usedSet.has(nums[i])
+            ) continue;
+            usedSet.add(nums[i]);
+            route.push(nums[i]);
+            backTracking(nums, i + 1, route);
+            route.pop();
+        }
+    }
+};
+```
+
 ### C 
+
 ```c
 int* path;
 int pathTop;