trie树,又名单词查找树。集训里有,就提前学了一下,不多说,直接贴代码。(但我感觉和普通树没什么区别。。。)
#include<iostream> #include<cstdio> #include<cstring> using namespace std; char s[100]; int n = 0,l,tot = 0; typedef struct node{ node *l[26];
int word = 0;//记录有几个单词的前缀是它 } *tree; tree head; void build(int a,int l,tree &p) {
p->word ++; if(a == l) return; if(p->l[s[a] - 'A'] == NULL) { p->l[s[a] - 'A'] = new node; for(int i = 0;i <= 25;i++) p->l[s[a]-'A']->l[i]=NULL; } build(a + 1,l,p->l[s[a] - 'A']); } void dfs(tree p) { tot ++; for(int i = 0;i <= 25;i++) { if(p->l[i] != NULL) dfs(p->l[i]); } } int main() { head = new node; //必须先打这一句 for(int i = 0;i <= 25;i++) head->l[i]=NULL; while(scanf("%s",s) != EOF) { build(0,strlen(s),head); } dfs(head); cout<<tot<<endl;//根节点去掉 return 0; } /* A AN ASP AS ASC ASCII BAS BASIC */