HDU1247 Hat’s Words

PS:  Trie树的应用。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
const int maxn = 50010;
const int MAX = 200;
//2014-04-05 Accepted	1247	15MS	7368K	2121 B	C++	Achiberx
struct node {
    int v;
    node* next[26];
};
node* root;
int cnt[MAX];

void Insert(char* str) {
    node* now = root;
    int len = strlen(str);
    for(int i = 0; i < len; i++) {
        int u = str[i]-‘a‘;
        if(now->next[u]==NULL) {
            node* t = new node;
            t->v = 0;
            memset(t->next, NULL, sizeof(t->next));
            now->next[u] = t;
        }
        now = now->next[u];
    }
    now->v = -1; // represent the ending of word.
}

bool query2(char* str) {
    node* now = root;
    int len = strlen(str);
    for(int i = 0; i < len; i++) {
        int u = str[i]-‘a‘;
        if(now->next[u] != NULL) {
            now = now->next[u];
            if(i==len-1 && now->v ==- 1) return true;
        } else  return false;
    }
    return false;
}

bool query(char* str) {
    vector<int> v;
    v.clear();
    node* now = root;
    int len = strlen(str);
    for(int i = 0; i < len; i++) {
        int u = str[i]-‘a‘;
        if(now->next[u] != NULL) {
            now = now->next[u];
            if(now->v==-1) {
                v.push_back(i);
            }
        } else break;
    }
    if(!v.size()) return false;
    char remain[100];
    memset(remain, ‘\0‘, sizeof(remain));
    for(int i = 0; i < (int)v.size(); i++) {
        int st = v[i];
        strcpy(remain, str+st+1);
        if(!strlen(remain)) return false;
        bool result = query2(remain);
        if(result) return true;
        else continue;
    }
    return false;
}

char lib[maxn+5][100];
int main()
{
    char str[100];
    int idx = 0;
    root = new node;
    root->v = 0;
    memset(root->next, NULL, sizeof(root->next));

    while(gets(str) && str[0]) {
        Insert(str);
        strcpy(lib[idx++], str);
    }
    for(int i = 0; i < idx; i++) {
        bool res = query(lib[i]);
        if(res) puts(lib[i]);
    }
    return 0;
}

HDU1247 Hat’s Words,布布扣,bubuko.com

HDU1247 Hat’s Words

原文：http://blog.csdn.net/achiberx/article/details/22984935