Recursion: Print a sequence first into the stack and then out of the stack all the possible __delete

Title: A sequence, such as 1,2,3. 1 after the stack, there are two cases: one, 2 into the stack, two, 1 out of the stack to the target array. These two types of energy are present at every point in the execution of the program, which results in a different print result. Requirements: Print out all possible output sequences

Train of thought: recursively iterate through all the solution space, pay attention to the time of recursion to restore each step of the environment. My program uses three arrays, source sequence src[], analog stack st[], target array dest[] (that is, the last array to print). where st[0] and dest[0 respectively represent the subscript of the last element of the current array, with an initial state of 0, indicating that there are no elements in the array.

C + + Implementation of the program:

StackInOrOut.cpp

#include <iostream> using namespace std;
void init (int *arr, int start, int end);
void initsrc (int *arr, int start, int end);
void print (int *arr, int start, int end);
void stackinorout (int *src, int *st, int *dest, int index, int size, BOOL flag);
	int main () {int size;
	cout << "Please input size of src:" << Endl;
	CIN >> size;
	int *src = new Int[size];
	int *st = new Int[size + 1], *dest = new Int[size + 1];
	INITSRC (src, 0, size-1);
	Init (ST, 0, size);
	Init (dest, 0, size);   Stackinorout (SRC, St, dest, 0, size, true);
	Just start into the stack, can not be out of the stack delete []src;
	delete []st;
delete []dest;  } void init (int *arr, int start, int end) {for (int i = start; I <= end; ++i) arr[i] = 0;} void initsrc (int *arr, 
int start, int end) {for (int i = start; I <= end; ++i) Arr[i] = i + 1;} void print (int *arr, int start, int end)
	{static int count = 1;
	cout << "Count =" << count << ", arr[0] =" << arr[0] << ' \ t '; for (int i = StarT I <= end;
	++i) cout << arr[i] << ";
	cout << Endl;
++count; } void Stackinorout (int *src, int *st, int *dest, int index, int size, BOOL flag) {if (index = = size) {if (flag = t
			Rue)//If the stack, print results, out of the stack directly exit {int j = dest[0];
			for (int i = st[0]; I!= 0-I.) DEST[++J] = St[i];
		Print (dest, 1, size);
	} return;		} if (true = = Flag) {St[++st[0]] = Src[index];
		Into the stack stackinorout (SRC, st, dest, Index + 1, size, true);
		Stackinorout (SRC, st, dest, Index + 1, size, false);						--ST[0];					Restore Top pointer} else {if (st[0]!= 0) {dest[++dest[0]] = st[st[0]--];
			Out stack top element to target array stackinorout (SRC, st, dest, Index, size, true);
			Stackinorout (SRC, st, dest, Index, size, false);										++ST[0];						Restore top pointer st[st[0]] = dest[dest[0]];										The problem here is that the original program did not restore the value of the elements in the stack, but restored the top pointer--dest[0]; Recover target array Top pointer}}}