n个元素进栈，输出所有出栈序列-卡特兰数-递归

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;


void printAllOutStackSeq( queue inQueue, int n, stack st, queue out )
{
	if( n <= 0 || ( inQueue.empty() && st.empty() && out.empty() ) )
	{
		return;
	}

	if( out.size() == n )
	{
		while( !out.empty() )
		{
			cout << out.front() << ' ';
			out.pop();
		}

		cout << endl;
		return;
	}

	stack stCopy = st;  // 备份一下，否则储转
	queue outCopy = out;

	if( !st.empty() ) // 出栈，将元素出栈，push到结果队列中
	{
		out.push( st.top() );
		st.pop();
		printAllOutStackSeq( inQueue, n, st, out );	
	}
	
	
	if( !inQueue.empty() ) // 入栈，将输入队列出队，进行入栈
	{
		stCopy.push( inQueue.front() );
		inQueue.pop();
		printAllOutStackSeq( inQueue, n, stCopy, outCopy );	
	}
	
	return;
}


int main()
{
	int ret = 0;
	
	int a[] = { 1, 2, 3, 4 };
	queue inQueue;

	for( int i = 0; i < 4; i++ )
	{
		inQueue.push( a[i] );
	}

	int n;
	stack st;
	queue out;

	printAllOutStackSeq( inQueue, 4, st, out );

	return ret;
}

/*
n个元素入栈，出栈序列个数： C(2n,n)/(n+1)
./a.out
1 2 3 4 
1 2 4 3 
1 3 2 4 
1 3 4 2 
1 4 3 2 
2 1 3 4 
2 1 4 3 
2 3 1 4 
2 3 4 1 
2 4 3 1 
3 2 1 4 
3 2 4 1 
3 4 2 1 
4 3 2 1 

./a.out|wc -l
14



*/