Uva10701 Pre, in and post

和Tree Recover基本类似，就改了一点而已

#include <iostream>
#include <string>
using namespace std;

string pr,in;
string postorder;
void process(string preord,string inord);
int main()
{
    int line,order;
    //freopen("D:\acm.txt","r",stdin);
    cin>>line;
    while(line--){
        cin>>order;
        cin>>pr>>in;
        postorder.clear();
        process(pr,in);
        cout<<postorder<<endl;
    }
    return 0;
}
void process(string preord,string inord){
    int Size = preord.size();
    if(Size>0){
        int p = inord.find(preord[0]);
        process(preord.substr(1,p),inord.substr(0,p));//左树
        process(preord.substr(p + 1,Size - (p + 1)),inord.substr(p + 1,Size - (p + 1)));//右树
        postorder.push_back(preord[0]);
    }
}