제출 #1173777

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1173777		ezzzay	Cryptography (NOI20_crypto)	C++20	5 / 100	174 ms	26352 KiB

Crypto

#include<bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define int long long
const int N=4e5;
int a[N];
int fct[N];
int bit[N];
void update(int idx, int val){
    while(idx<N){
        bit[idx]+=val;
        idx+= idx & -idx;
    }
}
int find(int idx){
    int s=0;
    while(idx>0){
        s+=bit[idx];
        idx-= -idx &idx;
    }
    return s;
}
signed main(){
    int n;
    cin>>n;
    map<int,int>mp;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        mp[a[i]];
    }
    fct[0]=1;
    for(int i=1;i<=n;i++)fct[i]=fct[i-1]*i;
    int id=1;
    for(auto it=mp.begin();it!=mp.end();it++){
        it->ss= id++;
    }
    for(int i=1;i<=n;i++){
        a[i]= mp[a[i]];
        update(a[i],1);
    }
    int ans=0;
    fct[0]=0;
    for(int i=1;i<=n;i++){
        int x= find(a[i])-1;
        
        ans+= fct[x]* (n-i);
        update(a[i],-1);
    }
    cout<<ans+1;;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 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