Submission #469546

#	Time	Username	Problem	Language	Result	Execution time	Memory
469546		FatihSolak	Rack (eJOI19_rack)	C++17	20 / 100	1 ms	204 KiB

rack

#include <bits/stdc++.h>
#define N 1000005
#define int long long
using namespace std;
const int mod = 1e9+7;
int pw(int b){
    int ret = 1;
    for(int i=0;i<b;i++){
        ret = min((int)2e18,ret*2);
    }
    return ret;
}
int pw2(int b){
    int ret = 1;
    for(int i=0;i<b;i++){
        ret = ret*2%mod;
    }
    return ret;
}
void solve(){
    int n,k;
    cin >> n >> k;
    int ans = 0;
    if(k > pw(n-1)){
        ans++;
        k -= pw(n-1);
    }
    int cnt = 1;
    if(k <= 2){
        cout << (1 + ans + (k-1)*pw2(n-1))%mod << "\n";
        return;
    }
    k -= 2;
    for(int i=2;;i++){
        cnt*=2;
        if(k <= cnt){
            cout << (1 + ans + pw2(n-i) + (k-1)/2*pw2(n-i+1) + (k%2==0) *pw2(n-1))%mod << "\n";
            break;
        }
        k -= cnt;
    }
}

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    #ifdef Local
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
    #endif
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    #ifdef Local
    cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 60