n个元素进栈，输出所有出栈序列-卡特兰数-递归

#include <iostream>#include <stack>#include <queue>#include <algorithm>#include <string.h>#include <cstdio>#include <stdlib.h>#include <cctype>#include <stack>#include <queue>using namespace std;void printAllOutStackSeq( queue<int> inQueue, int n, stack<int> st, queue<int> 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<int> stCopy = st;  // 备份一下，否则储转queue<int> 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<int> inQueue;for( int i = 0; i < 4; i++ ){inQueue.push( a[i] );}int n;stack<int> st;queue<int> 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.out1 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 -l14*/