【模板】字符串hash

洛谷P3370

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define sz 10010
#define ull unsigned long long
using namespace std;
int n, ans = 1;
const int base = 233;
ull a[sz];
char s[sz];
ull hash(char s[]) {
    int len = strlen(s);
    ull ans = 0;
    for(int i = 0; i < len; i++) ans = (ans*base+(ull)s[i]);
//一度不理解它怎么就转换成base进制的数了qaq不想承认自己是个傻子qaq
    return ans&0x7ffffff;
}
int main() {
    scanf("%d",&n);
    for(int i = 1; i <= n; i++) {
        scanf("%s",s);
        a[i] = hash(s);
    }
    sort(a+1,a+n+1);
    for(int i = 2; i <= n; i++) if(a[i] != a[i-1]) ans++;
    printf("%d",ans);
    return 0;
} 

 

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