Submission #1119003

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119003		Dan4Life	Rack (eJOI19_rack)	C++17	100 / 100	146 ms	504 KiB

rack

#include <iostream>
using namespace std;
using ll=long long;
ll n,k,l,r,M=1e9+7;
ll p(ll b){
	if(!b)return 1;
	ll x=p(b/2);x*=x;x%=M;
	return (x*(b&1?2:1))%M;
}
main(){
	cin>>n>>k,l=1,r=p(n);
	while(n--){
		if(k%2)k++,r=(r+M-p(n))%M;
		else l=(l+p(n))%M;k/=2;
	}
	cout<<l;
}

Compilation message (stderr)

rack.cpp:10:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   10 | main(){
      | ^~~~
rack.cpp: In function 'int main()':
rack.cpp:14:3: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
   14 |   else l=(l+p(n))%M;k/=2;
      |   ^~~~
rack.cpp:14:21: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   14 |   else l=(l+p(n))%M;k/=2;
      |                     ^

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