杭电2072 单词数(Trie tree或者STL)

来源：互联网发布：linux 查看网卡状态编辑：程序博客网时间：2024/05/18 12:34

->题目请戳这里<-

题目大意：中文题，不解释。

题目分析：字典树水过~

详情请见代码：

#include <iostream>#include<cstdio>#include<map>#include<string>#include<cstring>#include<cstdlib>#include<set>using namespace std;typedef struct node{    struct node *next[26];    int end;}tree;char s[100005];int len;int deep;int cnt;void init(tree *t){    t->end = 0;    int i;    for(i = 0;i < 26;i ++)        t->next[i] = NULL;}void del(tree *t){    int i;    for(i = 0;i < 26;i ++)        if(t->next[i] != NULL)            del(t->next[i]);    free(t);}void build(tree *t,int id){    if(t->next[s[id] - 'a'] == NULL)    {        t->next[s[id] - 'a'] = (tree *)malloc(sizeof(tree));        init(t->next[s[id] - 'a']);    }    if(s[id + 1] == ' ' || s[id + 1] == '\0')    {        if(t->next[s[id] - 'a']->end == 0)        {            t->next[s[id] - 'a']->end = 1;            cnt ++;        }        deep = id + 1;        return;    }    else        build(t->next[s[id] - 'a'],id + 1);}int main(){    int i;    tree *root = NULL;    while(gets(s) && strcmp(s,"#") != 0)    {        cnt = 0;        root = (tree *)malloc(sizeof(tree));        init(root);        len = strlen(s);        int flag;        for(i = 0;i < len;i ++)        {            if(s[i] == ' ')            {                while(s[i] == ' ')                    i ++;                i --;            }            else            {                deep = 0;                build(root,i);               // printf("deep:%d\n",deep);                i = (deep - 1);            }        }        printf("%d\n",cnt);        del(root);    }    return 0;}//0MS332K

这题数据应该很弱，字典树竟然只花了332K。。。

其实此题还有更简单解法，可以用STL的set水过~

详情请见代码：

#include <iostream>#include<cstdio>#include<map>#include<string>#include<cstring>#include<cstdlib>#include<set>using namespace std;set<string> lcm;string s;char str[100005];char tmp[100005];int main(){    int i,j;    while(gets(str),strcmp(str,"#") != 0)    {        lcm.clear();        i = 0;        while(str[i] == ' ')            i ++;        j = 0;        //printf("len:%d\ni:%d\n",strlen(str),i);        for(;i < strlen(str);i ++)        {            if(str[i] == ' ')            {                tmp[j] = '\0';                s = tmp;                lcm.insert(s);                j = 0;                while(str[i] == ' ')                    i ++;                i --;            }            else                tmp[j ++] = str[i];        }        if(j)        {            s = tmp;            lcm.insert(s);        }        printf("%d\n",lcm.size());    }    return 0;}//0MS364K