QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#164076#7046. Function!wifi32767#WA 1ms3724kbC++201.4kb2023-09-04 19:30:432023-09-04 19:30:43

Judging History

你现在查看的是最新测评结果

  • [2023-09-04 19:30:43]
  • 评测
  • 测评结果:WA
  • 用时:1ms
  • 内存:3724kb
  • [2023-09-04 19:30:43]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int MAX = 1e3 + 10, mod = 998244353;

ll n, k;
ll ans = 0;
ll safe_sqrt(ll x){
    ll lk = 0, rk = 2 * sqrt(x);
    while (lk < rk){
        ll mid = (lk + rk) >> 1;
        if (mid * mid >= x) rk = mid;
        else lk = mid + 1;
    }
    return lk;
}
ll cal(ll x){
    return 1ll * (2 * x * x * x + 3 * x * x + x) / 6;
}
void solve(){
    cin >> n;
    k = safe_sqrt(n);
    for (int i = 2; i <= k; ++ i){
        ll t = i - 1;
        int cnt = 1;
        while (t < n){
            ll m = (t + 1) * i - 1;
            if (m > n) ans = (ans + i * cnt * (n - t) % mod) % mod;
            else ans = (ans + i * cnt * (m - t) % mod) % mod;
            t = m;
            cnt ++;
        }
    }
    ans = (ans + (n + 1) * (n + k + 1) % mod * (n - k) / 2) % mod;
    ans += mod + cal(k) - cal(n);
    cout << ans % mod << endl;
}
void did(){
    ans = 0;
    for (int a = 2; a <= n; ++ a){
        for (int b = a; b <= n; ++ b){
            ans += a * (int)floor(log(b) / log(a));
            //cerr << ans << ' ';
        }
        //cerr << endl;
    }
    cout << ans;
}
signed main(){
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //cout << fixed << setprecision(20);
    //while (cin >> n)
    //int _;cin>>_;while(_--)
    	solve();
    //did();
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3568kb

input:

2

output:

2

result:

ok 1 number(s): "2"

Test #2:

score: 0
Accepted
time: 0ms
memory: 3640kb

input:

10

output:

236

result:

ok 1 number(s): "236"

Test #3:

score: 0
Accepted
time: 1ms
memory: 3664kb

input:

20

output:

1646

result:

ok 1 number(s): "1646"

Test #4:

score: 0
Accepted
time: 0ms
memory: 3632kb

input:

27

output:

3862

result:

ok 1 number(s): "3862"

Test #5:

score: 0
Accepted
time: 1ms
memory: 3708kb

input:

37

output:

9571

result:

ok 1 number(s): "9571"

Test #6:

score: 0
Accepted
time: 1ms
memory: 3636kb

input:

100

output:

175028

result:

ok 1 number(s): "175028"

Test #7:

score: 0
Accepted
time: 1ms
memory: 3724kb

input:

123

output:

322744

result:

ok 1 number(s): "322744"

Test #8:

score: -100
Wrong Answer
time: 1ms
memory: 3648kb

input:

2548

output:

-232574627

result:

wrong answer 1st numbers differ - expected: '765669726', found: '-232574627'