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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#594152 | #9309. Graph | caojc | WA | 1ms | 3804kb | C++20 | 3.2kb | 2024-09-27 19:43:01 | 2024-09-27 19:43:03 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define db(args...) { \
string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); \
stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); cout << '\n';}
void err(istream_iterator<string> it){}
template<typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
cout << *it << " = " << a << ' ';
err(++it, args...);
}
/*
min25筛第一部分,求质数的多项式和。
*/
vector<int> visi, pri; int cpri;
void init(int N) {
N++;
visi.assign(N, 0), pri.assign(N, 0);
for (int i = 2; i < N; i++) {
if (!visi[i]) {
visi[i] = i;
pri[++cpri] = i;
}
for (int j = 1; j <= cpri; j++) {
int id = pri[j] * i;
if (id >= N) break;
visi[id] = pri[j];
if (i % pri[j] == 0) break;
}
}
}
struct min25 {
// 幂次k=1
ll sn, n;
vector<int> id;
vector<ll> g;
int getid(ll x) {
if (x <= sn) return x;
return id[n / x];
}
min25(ll N) {
n = N;
sn = sqrt((long double)n);
init(2 * sn + 10); // todo
id.assign(sn + 1, 0);
g.assign(sn * 2 + 1, 0);
vector<ll> big(sn * 2 + 1), G(sn + 1);
for (int i = 2; i <= sn; i++) {
G[i] = G[i - 1] + (visi[i] == i);
}
for (int i = 1; i <= sn; i++) {
id[i] = 2 * sn + 1 - i;
big[i] = i, big[id[i]] = n / i;
}
for (int i = 1; i <= sn * 2; i++) {
g[i] = big[i] - 1; // todo 除了1所有数的k次方前缀和
}
for (int j = 1, beg = 1; pri[j] <= sn; j++) {
while (j > 1 && beg <= sn * 2 && pri[j] * 1ll * pri[j] > big[beg]) beg++;
for (int i = sn * 2; i >= beg; i--) {
ll k = 1; // todo pri[j] ^ k
g[i] = g[i] - k * (g[getid(big[i] / pri[j])] - G[pri[j - 1]]);
}
}
}
ll get(ll n) {
return g[getid(n)];
}
};
const int mod = 998244353;
ll ksm(ll a, ll b = mod - 2) {
a %= mod;
if (b == -1) return ksm(a);
ll res = 1;
while (b) {
if (b) res = res * a % mod;
a = a * a % mod, b /= 2;
}
return res;
}
void solve() {
ll n;
cin >> n;
min25 mi(n);
auto f = [&] (ll n) ->ll {
if (n <= 2) return 1;
ll c = mi.get(n) % mod - mi.get(n / 2) % mod;
c = (c + mod) % mod;
if (c == 0) return 1;
c++;
ll k = c + 1;
ll res = (n - c) * ksm(n, k - 2) % mod;
// db(n, res, c);
return res;
};
ll res = 1;
for (ll l = 1, r; l <= n; l = r + 1) {
r = n / (n / l);
ll resi = ksm(f(n / l), r - l + 1);
res = res * resi % mod;
}
cout << res << '\n';
}
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
int t = 1;
// cin >> t;
while (t--) solve();
return 0;
}
/*
g++ 1.cpp -std=c++20 -o 1 && ./1 < in.txt > out.txt
*/
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3804kb
input:
4
output:
8
result:
ok answer is '8'
Test #2:
score: 0
Accepted
time: 0ms
memory: 3584kb
input:
2
output:
1
result:
ok answer is '1'
Test #3:
score: -100
Wrong Answer
time: 1ms
memory: 3732kb
input:
123
output:
0
result:
wrong answer expected '671840470', found '0'