hdu 1251统计难题

来源：互联网发布：华云数据集团编辑：程序博客网时间：2024/04/28 03:20

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

字典树模版题

动态实现：

#include<stdio.h>#include<stdlib.h>#include<string.h>#define maxn 26struct node{int count;node *next[maxn];}*root;void insert(char str[]){int i,len = strlen(str);node *current,*newset;current = root;for(i = 0; i < len; i++){int k = str[i] - 'a';if(current->next[k] != NULL){current = current->next[k];current->count++;}else{newset = (node*)malloc(sizeof(node));memset(newset->next,NULL,sizeof(newset->next));current->next[k] =newset;current = newset;current->count = 1;}}}int find(char str[]){int i,len = strlen(str);if(len == 0)return 0;node *current = root;for(i = 0; i < len ; i++){int k = str[i] - 'a';if(current->next[k] != NULL)current = current->next[k];elsereturn 0;}return current->count;}int main(){char str[101];root = (node*)malloc(sizeof(node));memset(root->next,NULL,sizeof(root->next));while(gets(str) && str[0] != '\0')insert(str);while(~scanf("%s",str))printf("%d\n",find(str));return 0;}

静态实现：

#include<stdio.h>#include<string.h>struct node{int cnt;node *next[26];node(){cnt = 0;memset(next,NULL,sizeof(next));}}tree[400000];int cnt = 1;node *root;void insert(char *str){node *p = root;int m;while(*str){m = *str- 'a';if(p->next[m] == NULL)p->next[m] = &tree[cnt++];p = p->next[m];p->cnt ++;str++;}}int search(char *str){int m;node *p = root;while(*str){m = *str - 'a';if(p->next[m] == NULL)return 0;p = p->next[m];str++;}return p->cnt;}int main(){char str[15];root = tree;cnt = 1;while(gets(str) && str[0] != '\0')insert(str);while(~scanf("%s",str))printf("%d\n",search(str));return 0;}