UVA 536 TreeRocvery 树重建 （递归）

根据先序历遍和中序历遍输出后序历遍，并不需要真的建树，直接递归解决

#include<cstdio>

#include<cstring>



const int N = 30;

char preOrder[N];

char midOrder[N];



char S[N];

int top;

void solve(char *pre,char *mid,int len)//len>=1

{

   S[++top] = *pre;

   char *p = mid;

   while(*p != *pre) p++;

   p++;

   int tmp = p - mid;

   if(tmp < len)

      solve(pre + tmp, p ,len - tmp);

   if(tmp > 1)

      solve(pre + 1,mid,tmp - 1);

   return ;

}





int main()

{

   int len;

   while(~scanf("%s",preOrder)){

      scanf("%s",midOrder);

      top = 0;

      len = strlen(preOrder);

      solve(preOrder,midOrder,len);

      while(top) putchar(S[top--]);

      putchar('\n');

   }

}