P3370 【模板】字符串哈希题解

P3370 【模板】字符串哈希

题目描述

如题，给定 $N$ 个字符串（第 $i$ 个字符串长度为 $M_i$，字符串内包含数字、大小写字母，大小写敏感），请求出 $N$ 个字符串中共有多少个不同的字符串。

友情提醒：如果真的想好好练习哈希的话，请自觉。

输入格式

第一行包含一个整数 $N$，为字符串的个数。

接下来 $N$ 行每行包含一个字符串，为所提供的字符串。

输出格式

输出包含一行，包含一个整数，为不同的字符串个数。

输入输出样例 #1

输入 #1

5
abc
aaaa
abc
abcc
12345

输出 #1

4

说明/提示

数据范围

对于 $30\%$ 的数据：$N\le 10$，$M_i\approx 6$，$M_{\max }\le 15$。

对于 $70\%$ 的数据：$N\le 1000$，$M_i\approx 100$，$M_{\max }\le 150$。

对于 $100\%$ 的数据：$N\le 10000$，$M_i\approx 1000$，$M_{\max }\le 1500$。

样例说明

样例中第一个字符串 $\mathtt{abc}$ 和第三个字符串 $\mathtt{abc}$ 是一样的，所以所提供字符串的集合为 $\{\mathtt{aaaa},\mathtt{abc},\mathtt{abcc},12345\}$，故共计 $4$ 个不同的字符串。

拓展阅读

以下的一些试题从不同层面体现出了字符串哈希算法的正确性分析。

• P12197 Hash Killer I
• P12198 Hash Killer II
• P12199 （目前无解）Hash Killer III
• P12200 Hash Killer Extra
• P12201 Hash Killer Phantasm
• P7350 「MCOI-04」Dream and Strings

思路

直接使用map即可。

代码见下

#include<bits/stdc++.h> 
using namespace std;
long long n,db=0;
string s;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
//string s2;
map<string,bool> mp;
int main(){
	cin>>n;
    for(int i=1;i<=n;i++){
        cin>>s;
        if(mp[s]==0){
            db++;
            mp[s]=1;
        }
    }
    cout<<db<<endl;
	return 0;
}