根据二叉树的先序遍历序列和中序遍历序列求后序遍历序列

 1 #include <iostream>
 2 #include <string>
 3 
 4 using namespace std;
 5 
 6 void post_order(string pre, string in)
 7 {
 8     size_t len = pre.length();
 9     if(len)
10     {
11         if(len==1){cout<<pre; return;}
12         size_t loc = in.find(pre[0]);
13         post_order(pre.substr(1, loc), in.substr(0, loc));
14         post_order(pre.substr(loc+1, len-loc), in.substr(loc+1, len-loc));
15         cout<<pre[0];
16     }
17 }
18 
19 int main()
20 {
21     string pre, in;
22     while(cin>>pre>>in)    post_order(pre, in);
23     cout<<endl;
24     return 0;
25 }