Submission #537720

#	Time	Username	Problem	Language	Result	Execution time	Memory
537720		kabika	Cryptography (NOI20_crypto)	C++14	14 / 100	1071 ms	10232 KiB

Crypto

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr ll MOD = 1e9 + 7;

int main()
{
    int n;
    cin >> n;
    
    vector<ll> fact(n);
    fact[0] = 1;
    for(int i = 1; i < n; ++i)
        fact[i] = i*fact[i-1];
    
    vector<ll> p(n);
    for(auto& x : p)
        cin >> x;
    ll lex = 0;
    vector<ll> srt(p.begin(), p.end());
    sort(srt.begin(), srt.end());
    int i = 0;
    while(!srt.empty())
    {
        auto it = lower_bound(srt.begin(), srt.end(), p[i]);
        int pos = it - srt.begin();
        lex = (lex + pos*fact[n-i-1]) % MOD;
        srt.erase(it);
        ++i;
    }
    ++lex;
    
    cout << lex << '\n';
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 9 / 9
• Subtask 3: 0 / 10
• Subtask 4: 0 / 11
• Subtask 5: 0 / 21
• Subtask 6: 0 / 13
• Subtask 7: 0 / 19
• Subtask 8: 0 / 12