后序遍历序列

   编写一个程序，输入一颗二叉树的先序遍历和中序遍历，输出其后序遍历

#include<iostream>
#include<string>
using namespace std;
void   outPostOrder(string  pre, string mid)
{
	int len = pre.length();
	if (len == 1)
	{
		cout << pre[0];
		return;
	}
	int index = mid.find(pre[0]);
	string leftPre(pre, 1, index);
	string leftMid(mid, 0, index);
	string rightPre(pre, index + 1, len - index - 1);
	string rightMid(mid, index + 1, len - index - 1);
	if (leftPre.length() > 0)
		outPostOrder(leftPre, leftMid);
	if (rightPre.length() > 0)
		outPostOrder(rightPre, rightMid);
	cout << endl;
}
int main()
{
	string pre, mid;
	cout << "请输入先序遍历序列: ";
	cin >>pre;
	cout << "请输入中序遍历序列: ";
	cin >> mid;
	cout << "后序遍历序列为: ";
	outPostOrder(pre, mid);
	cout << endl;
	return 0;
}