Submission #369968

#	Time	Username	Problem	Language	Result	Execution time	Memory
369968		iliccmarko	Rack (eJOI19_rack)	C++14	100 / 100	19 ms	8172 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define INF 1000000000
#define LINF 1000000000000000LL
#define pb push_back
#define all(x) x.begin(), x.end()
#define len(s) (int)s.size()
#define test_case { int t; cin>>t; while(t--)solve(); }
#define single_case solve();
#define line cerr<<"----------"<<endl;
#define ios { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cerr.tie(NULL); }
#define mod 1000000007LL
const int N = 1e6 + 60;
ll n, k;
ll a[N];


int main()
{
    a[0] = 1LL;
    for(int i = 1;i<N;i++) a[i] = (a[i-1]*2LL)%mod;
    ios
    cin>>n>>k;
    ll stepen = 2LL;
    ll ind = n-1LL;
    ll l = 1LL;
    int par = 0;
    while(k%stepen==0)
    {
        l = (l+a[ind])%mod;
        if(k%(stepen*2LL)!=0){
            ind--;
            stepen*=2LL;
            break;
        }
        ind--;
        stepen*=2LL;
    }
    ind--;
    stepen*=2LL;
    while(true)
    {
        //cout<<ind<<endl;
        ll aa = k%(stepen/2LL);
        ll b = aa + stepen/2LL;
        if(k%stepen==b) l = (l+a[ind])%mod;
        ind--;
        if(stepen>k) break;
        stepen*=2LL;
    }

    cout<<l;





    return 0;
}

Compilation message (stderr)

rack.cpp: In function 'int main()':
rack.cpp:29:9: warning: unused variable 'par' [-Wunused-variable]
   29 |     int par = 0;
      |         ^~~

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