poj1002 Output Limit Exceeded

#include <iostream>
using namespace std;
#include <memory.h>
#include <string.h>

typedef struct node{
	char pbuf[20];
	int pcount;
	struct node* left;
	struct node* right;
}node;

void insertnode(node* ppar, node* pnew)
{
	if(strcmp(ppar->pbuf, pnew->pbuf)<0)
	{
		if(ppar->right!=NULL)
			insertnode(ppar->right, pnew);
		else
			ppar->right=pnew;
	}
	else if(strcmp(ppar->pbuf, pnew->pbuf)>0)
	{
		if(ppar->left!=NULL)
			insertnode(ppar->left, pnew);
		else
			ppar->left=pnew;
	}
	else
		ppar->pcount++;
}

void printout(node* p, int& flag)
{
	if(p->left!=NULL)
		printout(p->left, flag);

	if(p->pcount>1)
	{
		printf("%.3s-%s %d\n", p->pbuf, p->pbuf+3, p->pcount);
		flag = 1;
	}

	if(p->right!=NULL)
		printout(p->right, flag);
}
int main()
{
	char mapp[128];
	memset(mapp, 0, 128);
	
	int i =0;
	for(i='0'; i<='9'; i++)
		mapp[i] = i;
	
	memset(mapp+'A', '2', 3);
	memset(mapp+'D', '3', 3);
	memset(mapp+'G', '4', 3);
	memset(mapp+'J', '5', 3);
	memset(mapp+'M', '6', 3);
	memset(mapp+'P', '7', 1);
	memset(mapp+'R', '7', 2);
	memset(mapp+'T', '8', 3);
	memset(mapp+'W', '9', 3);

	node* phead = new node;
	memset((void*)phead, 0, sizeof(node));

	int n;
	cin>>n;
	
	char inbuf[20];
	for(i=0; i<n; i++)
	{
		memset(inbuf, 0, 20);
		cin>>inbuf;
		char* pin = inbuf;
		node* pnew = new node;
		memset((void*)pnew, 0, sizeof(node));
		pnew->pcount = 1;
		char* pout =pnew->pbuf;
		while(*pin)
		{
			if(mapp[*pin]!='\0'){
				*pout++ = mapp[*pin];
			}
			pin++;
		}

		insertnode(phead, pnew);
	}

	int flag =0;
	printout(phead, flag);
	
	if(flag==0)
		cout<<"No duplicates. ";

	return 0;
}

刚开始报Output Limit Exceeded，网上百度了许多，一个网页说说用二叉树，给过了

成绩很惨（查询网址http://poj.org/problemstatus?problem_id=1002&start=5000&orderby=time&language=-1）

1    2115891(55)    thisisatest    836K    30MS    G++    3108B     2007-04-21 00:20:30

2    10611620(318)    zjufan    4468K    32MS    C++    4305B     2012-08-05 17:13:38

...
16151    11010059    dragoo1    5736K    1391MS    C++     1697B     2012-11-12 22:09:22