字符串
Hash
#include <algorithm>
#include <cstring>
#include <iostream>
#include <vector>
#include <map>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const ll N = 1e5 + 9;
const ll mod = 100001333;
const ll P = 131;
ull Hash[N];
ull pp[N];
ll getlen(ll a, vector<ll> &v) {
ll ret = 0;
while (a) {
ret++;
v.push_back(a % 2);
a /= 2;
}
return ret;
}
char str[N];
map<ull, int>mp;
void solve() {
int t, m;
cin >> t ;
int ans = 0;
while (t--) {
cin >> (str + 1);
Hash[0] = 0;
ull p = P;
pp[0] = 1;
int n = strlen(str + 1);
for (int i = 1; i <= n; i++) {
pp[i] = pp[i - 1] * P;
Hash[i] = Hash[i - 1] * p + str[i];
}
if (!mp.count(Hash[n])) {
ans++;
mp[Hash[n]] = 1;
}
}cout << ans << endl;
}
signed main() {
ll t = 1; // cin >> t;
while (t--) {
solve();
}
}
由于单 \(hash\) 太容易被卡了,所以模数不要简单地自然溢出,要用 \(100001333\) 等不会被卡的模数。