trie树

参考资料:

http://www.docin.com/p-48431870.html

poj练习:

trie树（静态建树、动态建树） （2513, 3630, 1204, 2503）

 

以下是来自豆丁网的截图.

 

 

 

 

 

 

 

Trie树的实现.(这里只讨论简单Trie数)

1。结构体

//trie树结构体struct Trie{Trie *next[26];bool isWord;}Root;

2。插入操作

//插入操作(也是构建Trie树)void insert(char *tar){Trie* head = &Root;int id;while(*tar){id = *tar - 'a';if(head->next[id] == NULL)head->next[id] = new Trie();head = head->next[id];tar++;}head->isWord = true;}

 

3。查找操作

 

 //查找bool search(char *tar){Trie* head = &Root;int id;while(*tar){id = *tar - 'a';if(head->next[id] == NULL)return false;head = head->next[id];tar++;}if(head->isWord)return true;elsereturn false;}

 

poj 2503 解题报告

//trie#include<iostream>using namespace std;#define N 200000struct trieNode{ int next[26]; char word[12];};trieNode trie[N];int len = 1;void insert(char* fw,char* tar){ trieNode * p = &trie[0]; int id; while(*tar) { id = *tar-'a'; if(p->next[id] == -1) { p->next[id] = len; len++; } p = &trie[p->next[id]]; tar++; } strcpy(p->word, fw);}char* search(char* tar){ trieNode* p = &trie[0]; int id; while(*tar) { id = *tar -'a'; if(p->next[id] == -1) return NULL; p = &trie[p->next[id]]; tar++; } if(strlen(p->word) > 0) return p->word; else return NULL;}int main(){ char w[11], f[11], s[25]; int i, j;for(i=0; i<N; i++) { strcpy(trie[i].word,""); memset(trie[i].next, -1, sizeof(trie[i].next)); } while(gets(s) && s[0] != 0) { for(i=0; s[i]!=' '; i++) w[i] = s[i]; w[i] = 0; for(++i,j=0; s[i]; i++,j++) f[j] = s[i]; f[j] = 0; insert(w, f); } char* p; while(scanf("%s",&w) != EOF) { p = search(w); if(p != NULL) printf("%s/n", p); elseputs("eh"); } return 0;}//hash/*#include<iostream>using namespace std;#define MAX 200000struct Dic{char w[11], f[11];}dic[MAX/2];int hash[MAX];int main(){int i, j, k=0, hashValue;char s[25];memset(hash, -1, sizeof(hash));while(gets(s) && s[0] != 0){for(i=0; s[i]!=' '; i++)dic[k].w[i] += s[i];dic[k].w[i] += 0;for(++i,j=0; s[i]!='/0'; i++,j++)dic[k].f[j] += s[i];dic[k].f[j] += 0;i = hashValue = 0;while(dic[k].f[i]){hashValue += hashValue*26 + dic[k].f[i++];hashValue %= MAX;}while(hash[hashValue] != -1)hashValue = (hashValue+1)%MAX;hash[hashValue] = k;k++;}while(scanf("%s", s) != EOF){i = hashValue = 0;while(s[i]){hashValue += hashValue*26 + s[i++];hashValue %= MAX;}while(strcmp(dic[hash[hashValue]].f, s) != 0 && hash[hashValue] != -1)hashValue = (hashValue+1)%MAX;if(hash[hashValue] == -1)puts("eh");elseprintf("%s/n", dic[hash[hashValue]].w);}return 0;}*///STL map/*#include<iostream>#include<map>#include<string>using namespace std;int main(){int i;char s[25], c;map<string, string> map;string w, f, tmp;while(gets(s) && s[0] != 0){w = f = "";for(i=0; s[i]!=' '; i++)w += s[i];for(++i; s[i]!='/0'; i++)f += s[i];map[f] = w;}while(scanf("%s", s) != EOF){tmp = map[string(s)];if(tmp.size() == 0)puts("eh");elseprintf("%s/n", tmp.c_str());}return 0;}*/

 

poj 3630 Phone List

http://162.105.81.212/JudgeOnline/problem?id=3630

#include<iostream>using namespace std;#define MAX 100000struct Trie{int next[10];bool isPhoNum;};Trie trie[MAX];int len;void init(){len = 1;for(int i=0; i<MAX; i++){memset(trie[i].next, -1, sizeof(trie[i].next));trie[i].isPhoNum = 0;}}bool insert(char* tar){Trie* head = &trie[0];int id;while(*tar){id = *tar - '0';if(head->next[id] == -1)head->next[id] = len++;elseif(trie[head->next[id]].isPhoNum)return 1;head = &trie[head->next[id]];tar++;}head->isPhoNum = 1;for(id=0; id<10; id++)if(head->next[id] != -1)return 1;return 0;}int main(){int i, t, n, flag;char c[15];scanf("%d", &t);while(t--){init();flag = 0;scanf("%d", &n);for(i=0; i<n; i++){scanf("%s", c);if(insert(c)){puts("NO");for(++i; i<n ;i++)scanf("%*s");flag = 1;break;}}if(!flag)puts("YES");}return 0;}

 

poj 1035 Spell checker

http://162.105.81.212/JudgeOnline/problem?id=1035

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<math.h>#define MAXN 200002struct Trie{int next[26];bool isWord;}trie[MAXN];int index;struct Dic{char word[16];}dic[10001];void init(){index = 1;for(int i=0; i<MAXN; i++){memset(trie[i].next, -1, sizeof(trie[i].next));trie[i].isWord = 0;}}void insert(char *tar){Trie* root = &trie[0];int id;while(*tar){id = *tar - 'a';if(root->next[id] == -1)root->next[id] = index++;root = &trie[root->next[id]];tar++;}root->isWord = 1;}bool find(char *tar){Trie *root = &trie[0];int id;while(*tar){id = *tar - 'a';if(root->next[id] == -1){/*if(*(tar+1) == 0 && root->isWord)return 1;elsereturn 0;*/return 0;}tar++;root = &trie[root->next[id]];}if(root->isWord)return 1;return 0;}bool isLike(char *tar, char *match){int len_tar = strlen(tar);int len_match = strlen(match);if(abs(len_tar - len_match) >= 2)return 0;if(len_tar == len_match)//replace{int num = 0;for(int i=0; i<len_tar; i++){if(num > 1)return 0;if(tar[i] != match[i])num++;}if(num > 1)return 0;return 1;}else if(len_tar > len_match)//insert{bool vist = 0;int i, j;for(i=0,j=0; i<len_match; i++,j++){if(tar[j] != match[i]){if(vist)return 0;if(match[i] != tar[++j])return 0;elsevist = 1;}}return 1;}else//delete{int i, j;bool vist = 0;for(i=0, j=0; i<len_tar; i++,j++){if(tar[i] != match[j]){if(vist)return 0;if(match[++j] != tar[i])return 0;elsevist = 1;}}return 1;}}int main(){//freopen("in.txt", "r", stdin);int i = 0;char c[16];init();while(gets(dic[i].word) && dic[i].word[0] != '#')insert(dic[i++].word);while(gets(c) && c[0] != '#'){if(find(c))printf("%s is correct/n", c);else{printf("%s:", c);for(int I=0; I<i; I++){if(isLike(c, dic[I].word))printf(" %s", dic[I].word);}printf("/n");}}return 0;}