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 = ;
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 > )
      solve(pre + ,mid,tmp - );
   return ;
}

int main()
{
   int len;
   while(~scanf("%s",preOrder)){
      scanf("%s",midOrder);
      top = ;
      len = strlen(preOrder);
      solve(preOrder,midOrder,len);
      while(top) putchar(S[top--]);
      putchar('\n');
   }
}