Submission #267039

#	Time	Username	Problem	Language	Result	Execution time	Memory
267039		kimbj0709	Cryptography (NOI20_crypto)	C++14	100 / 100	306 ms	20176 KiB

Crypto

#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define maxn 300050
#define mod 1000000007
vector<int> seg(maxn*4,0);
void build(int node,int start,int end){
    if(start==end){
        seg[node] = 1;
        return;
    }
    int mid = (start+end)/2;
    build(node*2+1,start,mid);
    build(node*2+2,mid+1,end);
    seg[node] = seg[node*2+1]+seg[node*2+2];
    return;
}
void update(int node,int start,int end,int pos){
    if(start==end&&start==pos){
        seg[node]--;
        return;
    }
    int mid = (start+end)/2;
    if(pos<=mid){
        update(node*2+1,start,mid,pos);
    }
    else{
        update(node*2+2,mid+1,end,pos);
    }
    seg[node] = seg[node*2+1]+seg[node*2+2];
}
int query(int node,int start,int end,int rangemin,int rangemax){
    if(start>rangemax||end<rangemin){
        return 0;
    }
    if(start>=rangemin&&end<=rangemax){
        return seg[node];
    }
    int mid = (start+end)/2;
    return query(node*2+1,start,mid,rangemin,rangemax)+query(node*2+2,mid+1,end,rangemin,rangemax);
}
int32_t main(){
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int no_of_input;
    vector<int> vect1;
    vector<int> vect2;
    int input;
    cin >> no_of_input;
    for(int i=0;i<no_of_input;i++){
        cin >> input;
        vect1.push_back(input);
        vect2.push_back(input);
    }
    sort(vect2.begin(),vect2.end());
    build(0,0,vect1.size()-1);
    /*for(auto k:vect2){
        cout << k << " ";
    }
    cout << "--\n";*/
    for(int i=0;i<vect1.size();i++){
        int temp = vect1[i];
        vect1[i] = lower_bound(vect2.begin(),vect2.end(),temp)-vect2.begin();
    }
    vector<int> fact(maxn,0);
    fact[1] = 1;
    for(int i=2;i<fact.size();i++){
        fact[i] = fact[i-1]*i;
        fact[i] %= mod;
    }
    int sum = 0;
    for(int i=0;i<vect1.size();i++){
        int currsmaller = 0;
        if(vect1[i]!=0){
            currsmaller = query(0,0,vect1.size()-1,0,vect1[i]-1);
        }
        sum += fact[no_of_input-i-1]*currsmaller;
        sum %= mod;
        update(0,0,vect1.size()-1,vect1[i]);
    }
    sum++;
    sum %= mod;
    cout << sum;
}

Compilation message (stderr)

Crypto.cpp: In function 'int32_t main()':
Crypto.cpp:62:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |     for(int i=0;i<vect1.size();i++){
      |                 ~^~~~~~~~~~~~~
Crypto.cpp:68:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |     for(int i=2;i<fact.size();i++){
      |                 ~^~~~~~~~~~~~
Crypto.cpp:73:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |     for(int i=0;i<vect1.size();i++){
      |                 ~^~~~~~~~~~~~~

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