hdu1305字典树

hdu1305

#include
using namespace std;
struct trie
{
	int num;
	trie *child[2];
	trie()
	{
		for(int i=0;i<2;i++)	child[i]=0;
		num=0;
	}
} *root;
int flag;
void Insert(char *x)
{
	int k=0;trie *p=root;
	while(x[k]!='\0')
	{
		if(p->child[x[k]-'0']==0)
			p->child[x[k]-'0']=new trie;
		p=p->child[x[k]-'0'];
		if(p->num==2){
			flag=1;
			k++;
			continue;
		}
		if(p->num==1){
			if(x[k+1]=='\0')	flag=1;
			k++;
			continue;
		}
		p->num=1;
		k++;
	}
	p->num=2;
}
void Free(trie *p)
{
	for(int i=0;i<2;i++)
		if(p->child[i]) Free(p->child[i]);
	delete p;
}

int main()
{
	char x[10];
	int t=1;
	root=new trie;flag=0;
	while(scanf("%s",x)!=EOF)
	{
		if(x[0]=='9')
		{
			if(flag)	printf("Set %d is not immediately decodable\n",t++);
			else		printf("Set %d is immediately decodable\n",t++);
			flag=0;			Free(root);
			root=new trie;
			continue;
		}
		Insert(x);
	}
	return 0;
}