HDU 1251 Trie树模板题

Posted 2020-08-09 掉血菜鸡煮熟中

1、HDU 1251 统计难题  Trie树模板题，或者map

2、总结：用C++过了，G++就爆内存。。

题意：查找给定前缀的单词数量。

#include<iostream>
#include<cstring>
#include<cmath>
#include<queue>
#include<algorithm>
#include<cstdio>
#define max(a,b) a>b?a:b
#define F(i,a,b) for(int i=a;i<=b;i++)
#define mes(a,b) memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
#define LL long long
using namespace std;
const int N=10010,MAX=1000100;

struct Node
{
    int count;
    Node *child[26];
    Node(){
        mes(child,NULL);
        count=0;
    }
};

Node *root=new Node,*current;
void insert(char *str)
{
    current=root;
    for(int i=0;str[i];++i){
        int m=str[i]-‘a‘;
        if(current->child[m]==NULL){
            current->child[m]=new Node;
        }
        current=current->child[m];
        current->count++;
    }
}

int search(char *str)
{
    current=root;
    for(int i=0;str[i];++i){
        int m=str[i]-‘a‘;
        if(current->child[m]==NULL)
            return 0;
        current=current->child[m];
    }
    return current->count;
}

int main()
{
    char str[20];
    while(gets(str),*str)
        insert(str);
    while(gets(str))
        printf("%d\n",search(str));

    return 0;
}

View Code