pku 2418 Hardwood Species 字典树

http://poj.org/problem?id=2418

字典数编号，统计每个单词出现的次数，然后计算频率：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#define maxn 10007
using namespace std;


struct node
{
    int flag;
    node *next[100];
}*head,H[999999];
int pos;
int L;
struct mm
{
    char s[33];
}pp[maxn];
int cmp(mm a,mm b)
{
    return strcmp(a.s,b.s) < 0;
}
node* newnode()
{
    node *q = &H[pos++];
    for (int i = 0; i< 100; ++i)
    q->next[i] = NULL;
    q->flag = 0;
    return q;
}
void insert(char *s)
{
    int i,k;
     //printf(">>%s\n",s);
    int len = strlen(s);
    node *p = head;
    for (i = 0; i < len; ++i)
    {
        k = s[i] - 32;
        if (p->next[k] == NULL)
        p->next[k] = newnode();
        p = p->next[k];
    }
    if (p->flag == 0)
    {
        strcpy(pp[L++].s,s);
        p->flag++;
    }
    else
    p->flag++;

}
int find(char *s)
{
    int i,k;
    int len = strlen(s);
    node *p = head;
    for (i = 0; i < len; ++i)
    {
        k = s[i] - 32;
        if (p->next[k] == NULL)
        {
            return 0;
        }
        p = p->next[k];
    }
    return p->flag;
}

int main()
{
    //freopen("in.txt","r",stdin);
     char ch[33];
     L = pos = 0;
     head = &H[pos++];
     int sum = 0;
    while (gets(ch) != NULL)
    {
        sum++;
        insert(ch);
    }
    sort(pp,pp + L,cmp);
    for (int i = 0; i < L; ++i)
    {
        double num = find(pp[i].s);
        printf("%s %.4lf\n",pp[i].s,100.0*num/(1.0*sum));
    }
    return 0;
}