Submission #1280294

#	Time	Username	Problem	Language	Result	Execution time	Memory
1280294		Kerim	Rack (eJOI19_rack)	C++17	100 / 100	5 ms	592 KiB

rack

#include "bits/stdc++.h"

using namespace std;
const int MOD = 1e9+7;
int mod(int x){
	if (x >= MOD)
		x -= MOD;
	return x;
}
int main(){
	int n, a = 0, pw = 1;
	long long k;
	scanf("%d%lld", &n, &k);
	k -= 1;
	for (int i = 0; i < n; i++){
		if (n-i < 61 and k>>(n-i-1)&1)
			a = mod(a + pw);
		pw = mod(pw+pw);
	}
	printf("%d\n", mod(a+1));
}

Compilation message (stderr)

rack.cpp: In function 'int main()':
rack.cpp:13:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |         scanf("%d%lld", &n, &k);
      |         ~~~~~^~~~~~~~~~~~~~~~~~

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