base取个131,13331……都可以
unsigned long long自然取模的话容易被卡

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define LL long long
#define ULL unsigned long long
ULL H[100000];
ULL base=13331;
inline ULL Hash(char *s)
{
    ULL h=0;
    int len=strlen(s);
    for(int i=0;i<len;i++)
    {
        h=h*base+s[i]-'0';
    }
    return h;
}

int main()
{
    int n;
    cin>>n;
    char s[2000];
    for(int i=1;i<=n;i++)
    {
        scanf("%s",s);
        H[i]=Hash(s);
    }
    sort(H+1,H+n+1);
    int m=unique(H+1,H+n+1)-H-1;
    printf("%d\n",m);
    return 0;
}