uva 536

#include <iostream>#include <string>#include <string.h>using namespace std;void solve(char *pr,char *in,int length){    if(length==0) return ;    char a=*pr;    int index=0;    for(;index<length;index++)        if(in[index]==a) break;    solve(pr+1,in,index);    solve(pr+index+1,in+index+1,length-index-1);    cout<<a;}int main(){    string s1,s2;    char pr[70],in[70];    while(cin>>s1>>s2)    {        strcpy(pr,s1.c_str());        strcpy(in,s2.c_str());        solve(pr,in,s1.length());        cout<<endl;    }    return 0;}

这道题应该回头看……再想想递归和代码顺序，思考建立树

public static void preorder_traversal(tree t)        {            if (t == null)                return;            else            {                if (t.data != null)                Console.Write(t.data+"  ");                preorder_traversal(t.lchild);                preorder_traversal(t.rchild);            }        }