Submission #329785

#	Time	Username	Problem	Language	Result	Execution time	Memory
329785		JiratQ	Cryptography (NOI20_crypto)	C++14	14 / 100	1090 ms	20700 KiB

Crypto

#include<bits/stdc++.h>
using namespace std;
int dp[30010];

int fac(int n){
    if(dp[n]!=0) return dp[n]%1000000009;
    if(n==0) return 1;
    return dp[n]=fac(n-1)%1000000009*n%1000000009;
}

main(){
    int n;
    cin >> n;
    vector<int> vec;
    for(int i=0;i<n;i++){
        int k;
        cin >> k;
        vec.emplace_back(k);
    }
    vector<int> v=vec;
    sort(v.begin(),v.end());
    map<int,int> mapp;
    int cnt=1;
    for(int i=0;i<n;i++){
        mapp[v[i]]=cnt;
        cnt++;
    }
    for(int i=0;i<n;i++){
        vec[i]=mapp[vec[i]];
    }
    /*for(int i=0;i<n;i++){
        cout << vec[i] << " ";
    }
    cout << endl;*/
    map<int,int> m;
    int ans=0;
    for(int i=0;i<n;i++){
        int use=vec[i];
        int c=0;
        for(auto& k:m){
            if(use>k.first){
                c++;
            }
        }
        m[use]=1;
        ans += (use-1-c) * fac(n-1-i);
    }
    cout << ans+1;
}
//

Compilation message (stderr)

Crypto.cpp:11:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   11 | main(){
      |      ^

• 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