cp/cses/range-queries/static-range-minimum-queries.cc
2025-02-28 11:35:58 -05:00

111 lines
2.3 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;
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());
}
#define prln(...) std::println(__VA_ARGS__)
#define pr(...) std::print(__VA_ARGS__)
#ifdef LOCAL
#define dbgln(...) std::println(__VA_ARGS__)
#define dbg(...) std::print(__VA_ARGS__)
#endif
using ll = long long;
using ld = long double;
template <typename T>
using v = std::vector<T>;
template <typename T, size_t N>
using r = std::array<T, N>;
template <typename T1, typename T2>
using p = std::pair<T1, T2>;
#define ff first
#define ss second
#define eb emplace_back
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
// }}}
template <typename T>
struct sparse_table {
sparse_table(std::vector<T> const& ts)
: table(floor(__lg(max(1, static_cast<int>(ts.size())))) + 1,
std::vector<T>(ts.size())) {
for (size_t i = 0; i < ts.size(); ++i) {
table[0][i] = ts[i];
}
for (size_t j = 1; j < table.size(); ++j) {
for (size_t i = 0; i + (1 << (j - 1)) < ts.size(); ++i) {
table[j][i] = merge(table[j - 1][i], table[j - 1][i + (1 << (j - 1))]);
}
}
}
[[nodiscard]] T query(size_t const l, size_t const r) const {
if (!(0 <= l && r < table[0].size())) {
return 0;
}
int k = floor(__lg(r - l + 1));
return merge(table[k][l], table[k][r - (1 << k) + 1]);
}
private:
[[nodiscard]] inline T merge(T const& x, T const& y) const noexcept {
return min(x, y);
}
std::vector<std::vector<T>> table;
};
void solve() {
int n, q;
cin >> n >> q;
v<ll> a(n);
for (auto& e : a)
cin >> e;
sparse_table<ll> st(a);
while (q--) {
int l, r;
cin >> l >> r;
--l;
--r;
cout << st.query(l, r) << endl;
}
}
int main() { // {{{
cin.tie(nullptr)->sync_with_stdio(false);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
// }}}