Recursion Final

Recursion/P27_All_Sorted.cpp

@@ -1,9 +1,38 @@
 //For a,b,c we have sort abc acb bac bca cab cba(6 kinds) This Program is to sort all of the kinds
 #include <iostream>
-
 using namespace std;
+// 递减n叉树
+// 可能需要包展开，这里先不写，先以3个为主
+template<typename T>
+T* sort(int n, int l, T* tmp, bool* used, T* arr){
+	if(n == l){
+		cout << "[";
+		for(int i = 0;i < n; i++){
+		cout << tmp[i] <<" ";
+		}
+		cout << "]" << endl;
+	}
+
+	for(int i = 0;i < l; i++){
+		if(used[i] == false){
+			tmp[n] = arr[i];
+			used[i] = true;
+			sort(n + 1, l, tmp, used, arr);
+			used[i] = false; //是否可以删除？不可以，回溯本节点要用
+		}
+	}
+}
+
 
 int main() {
-
+	int n;
+	cin >> n;
+	int* tmp = new int[n];
+	int* arr = new int[n];
+	for(int i = 0;i < n; i++){
+		cin >> arr[i];
+	}
+	bool* used = new bool[n];
+	sort(0, n, tmp, used, arr);
 	return 0;
-}
+}