字符串应用（3）公共前缀

HDU1251

代码风格有问题：root与p换一下看起来更好

#include <cstdio>
#include <string>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

struct Trie
{
    int value;             //当前前缀出现次数
    struct Trie *next[26];
};


Trie *p;
char str[15];

struct Trie *CreateTree()
{
    struct Trie *root=(struct Trie*)malloc(sizeof(struct Trie));
    root->value=1;
    for (int i=0;i<26;i++)
        root->next[i]=NULL;
    return root;
}

void Insert()
{
    Trie *root=p;
    int len=strlen(str);
    for (int i=0;i<len;i++)
    {
        int id=str[i]-'a';
        if (root->next[id] == NULL)
        {
            root->next[id]=CreateTree();
            root=root->next[id];
        }
        else
        {
            root=root->next[id];
            (root->value)++;//每次都加一，统计所有当前字符串下的前缀
        }
    }
}
int Find()
{
    Trie *root=p;
    int len=strlen(str);
    for (int i=0;i<len;i++)
    {
        int id=str[i]-'a';
        if (root->next[id] == NULL) return 0;
        else root=root->next[id];
    }
    return root->value;
}

int main()
{
    p=CreateTree();
    while (gets(str),strcmp(str,"")!=0) Insert();
    while (scanf("%s",str)!=EOF) cout<<Find()<<endl;
    return 0;
}