fix(go): record slice array result, fixed #1075 (#1087)

codes/go/chapter_backtracking/preorder_traversal_iii_compact.go

@@ -18,7 +18,7 @@ func preOrderIII(root *TreeNode, res *[][]*TreeNode, path *[]*TreeNode) {
 	*path = append(*path, root)
 	if root.Val.(int) == 7 {
 		// 记录解
-		*res = append(*res, *path)
+		*res = append(*res, append([]*TreeNode{}, *path...))
 	}
 	preOrderIII(root.Left, res, path)
 	preOrderIII(root.Right, res, path)

codes/go/chapter_backtracking/preorder_traversal_iii_template.go

@@ -15,7 +15,7 @@ func isSolution(state *[]*TreeNode) bool {
 
 /* 记录解 */
 func recordSolution(state *[]*TreeNode, res *[][]*TreeNode) {
-	*res = append(*res, *state)
+	*res = append(*res, append([]*TreeNode{}, *state...))
 }
 
 /* 判断在当前状态下，该选择是否合法 */