cp/codeforces/928/e.cc
2025-08-24 14:47:38 -05:00

109 lines
1.9 KiB
C++

#include <bits/stdc++.h> // {{{
// https://codeforces.com/blog/entry/96344
#pragma GCC optimize("O2,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
using f64 = double;
using f128 = long double;
#if __cplusplus >= 202002L
template <typename T>
constexpr T MIN = std::numeric_limits<T>::min();
template <typename T>
constexpr T MAX = std::numeric_limits<T>::max();
template <typename T>
[[nodiscard]] static T sc(auto&& x) {
return static_cast<T>(x);
}
template <typename T>
[[nodiscard]] static T sz(auto&& x) {
return static_cast<T>(x.size());
}
#endif
static void NO() {
std::cout << "NO\n";
}
static void YES() {
std::cout << "YES\n";
}
template <typename T>
using vec = std::vector<T>;
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define ff first
#define ss second
#ifdef LOCAL
#define db(...) std::print(__VA_ARGS__)
#define dbln(...) std::println(__VA_ARGS__)
#else
#define db(...)
#define dbln(...)
#endif
// }}}
void solve() {
u64 n, k;
cin >> n >> k;
/*
initially lays down ceil(n / 2.0) cards
if found, its just 2 * k
n - ceil(n / 2.0) left
lays down 2 * odds
note: only odd # turns matter
n = 24
1 3 5 7 9 11 13 15 17 19 21 23 -> 2 4 6 8 10 12 ... left
2 6 10 14
div. both sides by 2:
1 2 3 4 5 6 <- n - ceil(n / 2.0) left
continue, log(n) itme
3 9 ... <- don't matter
div by 2
*/
u64 multiplier = 1;
while (k > (u64)ceil(n / 2.0)) {
k -= (u64)ceil(n / 2.0);
n -= (u64)ceil(n / 2.0);
multiplier *= 2;
}
println("{}", multiplier * (1 + 2 * (k - 1)));
}
int main() { // {{{
cin.tie(nullptr)->sync_with_stdio(false);
cin.exceptions(cin.failbit);
u32 tc = 1;
cin >> tc;
for (u32 t = 0; t < tc; ++t) {
solve();
}
return 0;
}
// }}}