HDU 3791 二叉搜索树

#include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;

typedef struct Node
{
Node *l,*r;
int num;
}*tree;

char f1[11],f2[11],l1[11],l2[11];
int cnt;

void insert(tree *T,int num)    //创建二叉树
{
if ((*T) != NULL)
{
if (num < (*T)->num)
{
insert(&(*T)->l,num);
}
else
insert(&(*T)->r,num);
}
else
{
*T = (tree)malloc(sizeof(Node));
(*T)->num = num;
(*T)->l = NULL;
(*T)->r = NULL;
}
}
//
// void insert(tree T,int num)    //创建二叉树
// {
//     if ((T) != NULL)
//     {
//         if (num < (T)->num)
//         {
// 			insert(T->l,num);
//         }
// 		else
// 			insert(T->r,num);
//     }
// 	else
// 	{
//         T = (tree)malloc(sizeof(Node));
// 		T->num = num;
// 		T->l = NULL;
// 		T->r = NULL;
// 	}
// }

void pre_order(tree T,char f[])    //先序遍历,将遍历后的数据存在f数组中
{
if (T)
{
f[cnt++] = T->num + '0';
pre_order(T->l,f);
pre_order(T->r,f);
}
}

void post_order(tree T,char f[])    //后序遍历
{
if (T)
{
pre_order(T->l,f);
pre_order(T->r,f);
f[cnt++] = T->num + '0';
}
}

int main()
{
int n,i,k;
string str;
tree T=NULL;
tree T1=NULL;
while (cin>>n,n)
{
cin>>str;

for (i=0;i<str.length();i++)
{
insert(&T,str[i]-'0');
}
cnt = 0;
pre_order(T,f1);
f1[cnt] = 0;           //易错点
cnt = 0;
post_order(T,l1);
l1[cnt] = 0;

for (i=0;i<n;i++)
{
cin>>str;
memset(f2,0,sizeof(f2));
memset(l2,0,sizeof(l2));
for (k=0;k<str.length();k++)
{
insert(&T1,str[k]-'0');
}
cnt = 0;
pre_order(T1,f2);
f2[cnt] = 0;
cnt = 0;
post_order(T1,l2);
l2[cnt] = 0;
if (strcmp(f1,f2) != 0 || strcmp(l1,l2) != 0)
{
cout<<"NO"<<endl;
}
else
cout<<"YES"<<endl;
free(T1);
T1=NULL;
}
free(T);
T=NULL;
}
return 0;
}

#include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;

char tree1[1100],tree2[3000],tree3[3000];

void buildtree(char *temtree,int pos,char data)
{
if (temtree[pos] == '.')
{
temtree[pos] = data;
return ;
}
if (temtree[pos] < data)
{
buildtree(temtree,pos*2+1,data);
}
else
if (temtree[pos] > data)
{
buildtree(temtree,pos*2,data);
}
}

int main()
{
int n,i,k;
while (cin>>n,n)
{
memset(tree2,'.',sizeof(tree2));
cin>>tree1;
for (i=0;i<strlen(tree1);i++)
{
buildtree(tree2,1,tree1[i]);
}
for (i=0;i<n;i++)
{
cin>>tree1;
memset(tree3,'.',sizeof(tree3));   //易错点
for (k=0;k<strlen(tree1);k++)
{
buildtree(tree3,1,tree1[k]);
}
if (strcmp(tree2,tree3))
{
cout<<"NO"<<endl;
}
else
cout<<"YES"<<endl;
}
}
return 0;
}