字典樹

http://acm.hdu.edu.cn/showproblem.php?pid=1251

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
using namespace std;
class Node
{
public:
	Node(char c)
	{
		s = c;
		prefix = 0;
		isword = false;
		memset(next, 0, sizeof(next));
	}
	char s;
	int prefix;
	bool isword;
	Node * next[26];
}; 
void insert(Node *p, char *str) {//插入
	int i, x;
    for(i = 0; str[i]; i++) {
        x = str[i] - 'a';
        if (!p->next[x])
			p->next[x] = new Node(str[i]);
        p = p->next[x];
        p->prefix++;
    }
    p->isword = true;
}
 
bool search(Node *p, char* str) {//查找
	int i, x;
    for(i = 0; str[i]; i++) {
        x = str[i] - 'a';
        if (!p->next[x])
            return false;
        p = p->next[x];
    }//for(i)
    return p->isword;
}
 
int count(Node *p, char *str) {//統計後綴
	int i, x;
    for(i = 0; str[i]; i++) {
        x = str[i] - 'a';
        if (!p->next[x])
            return 0;
        p = p->next[x];
    }//for(i)
    return p->prefix;
}
 
int main() {
	Node * root = new Node(0);
    char str[1024];
 
    while (gets(str), strcmp(str, "")) {
        insert(root, str);
    }
 
    while (gets(str)) {
        printf("%d\n", count(root,str));
    }
	return 0;
}