添加（0112.路径总和 ii）：增加typescript版本

problems/0112.路径总和.md

@@ -852,7 +852,39 @@ function hasPathSum(root: TreeNode | null, targetSum: number): boolean {
 
 > 0112.路径总和 ii
 
+**递归法：**
 
+```typescript
+function pathSum(root: TreeNode | null, targetSum: number): number[][] {
+    function recur(node: TreeNode, sumGap: number, routeArr: number[]): void {
+        if (
+            node.left === null &&
+            node.right === null &&
+            sumGap === 0
+        ) resArr.push([...routeArr]);
+        if (node.left !== null) {
+            sumGap -= node.left.val;
+            routeArr.push(node.left.val);
+            recur(node.left, sumGap, routeArr);
+            sumGap += node.left.val;
+            routeArr.pop();
+        }
+        if (node.right !== null) {
+            sumGap -= node.right.val;
+            routeArr.push(node.right.val);
+            recur(node.right, sumGap, routeArr);
+            sumGap += node.right.val;
+            routeArr.pop();
+        }
+    }
+    const resArr: number[][] = [];
+    if (root === null) return resArr;
+    const routeArr: number[] = [];
+    routeArr.push(root.val);
+    recur(root, targetSum - root.val, routeArr);
+    return resArr;
+};
+```
 
 ## Swift