update

Video.xaml.cs

@@ -92,7 +92,7 @@ namespace VideoConcat
             {
                 string mp4Path = $"{Directory.GetCurrentDirectory()}\\temp\\";
 
-                DirectoryInfo directoryInfo = new DirectoryInfo(mp4Path);
+                DirectoryInfo directoryInfo = new(mp4Path);
 
                 FileInfo[] files = directoryInfo.GetFiles("*.mp4"); // 获取指定目录下的所有 txt 文件
 
@@ -321,7 +321,7 @@ namespace VideoConcat
             {
                 ls.Add(new List<string>(item.Value));
             }
-            List<List<string>> permutations = CalculatePermutations(ls);
+            List<List<string>> permutations = GenerateAllPermutations(ls);
 
 
             return permutations;
@@ -352,6 +352,32 @@ namespace VideoConcat
 
 
 
+            return result;
+        }
+
+
+        static List<List<string>> GenerateAllPermutations(List<List<string>> ballInBoxes)
+        {
+            if (ballInBoxes.Count == 0)
+            {
+                return [[]];
+            }
+
+            List<string> firstBoxBall = ballInBoxes[0];
+            List<List<string>> remainingBoxes = ballInBoxes.GetRange(1, ballInBoxes.Count-1);
+
+            List<List<string>> subPermutations = GenerateAllPermutations(remainingBoxes);
+
+            List<List<string>> result = [];
+            foreach (var firstItem in firstBoxBall)
+            {
+                foreach (var subPermutation in subPermutations)
+                {
+                    List<string> newPermutation = [firstItem, .. subPermutation];
+                    result.Add(newPermutation);
+                }
+            }
+
             return result;
         }
     }