P3370 【模板】字符串哈希 - 洛谷 | 计算机科学教育新生态 (luogu.com.cn)

字符串哈希法

#define _CRT_SECURE_NO_WARNINGS 1. 
#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long ULL;
typedef long long LL;
const int N = 10001;
const int P = 233;
LL h[N], p[N];
char a[N];
ULL haxi(char s[])
{
	ULL len = strlen(s);
	ULL ans = 0;
	for (LL i = 0; i < len; i++)
	{
		ans =   P*ans +(ULL)s[i];
	}
	return ans;
}
int main()
{
	//cin.tie(nullptr)->sync_with_stdio(false);
	int n; scanf("%d",&n);
	for (int i = 1; i <= n; i++)
	{
		scanf("%s", a);
		h[i] = haxi(a);
	}

	sort(h + 1, h + 1 + n);
	LL ans = 1;
	for (LL i = 1; i <n; i++)
	{
		if (h[i] != h[i + 1])ans++;
	}
	cout << ans;
	return 0;
}

当然,想写简单点也有其他方法:

set

#include<bits/stdc++.h>
using namespace std;
set<string>se;
int main()
{
	int n;cin>>n;
	for(int i=1;i<=n;i++)
	{
		string s;cin>>s;
		se.insert(s);
	}
	cout<<se.size();
	return 0;
}