Submission #530100

#	Time	Username	Problem	Language	Result	Execution time	Memory
530100		tkwiatkowski	Rack (eJOI19_rack)	Cpython 3	100 / 100	322 ms	2844 KiB

rack

MOD = 10**9 + 7

def solve():
	n, k = map(int, input().split())
	k -= 1
	ans = 1
	for i in range(n):
		if (k % 2 == 0):
			ans = (2*ans) % MOD
		else:
			ans = (2*ans + 1) % MOD
		k //= 2;

	pow2 = 1
	for i in range(n):
		pow2 = (2*pow2) % MOD
	print((ans - pow2 + 1) % MOD)

solve()

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