feat(cses): range queries

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cses/range-queries/dynamic-range-minimum-queries.cc

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+#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 segment_tree {
+ public:
+  explicit segment_tree(std::vector<T> const& ts) : n(ts.size()) {
+    tree.resize(4 * n);
+    build(1, 0, n - 1, ts);
+  }
+
+  [[nodiscard]] T const query(int const l, int const r) const {
+    if (!(0 <= l && l <= r && r < static_cast<int>(n))) {
+      throw std::out_of_range(
+          "cannot query segment tree of size " + std::to_string(n) +
+          " at range [" + std::to_string(l) + ", " + std::to_string(r) + "]");
+    }
+
+    return query(1, 0, n - 1, l, r);
+  }
+
+  void update(int i, T const& t) {
+    if (!(0 <= i && i < static_cast<int>(n))) {
+      throw std::out_of_range("cannot update segment tree of size " +
+                              std::to_string(n) + " at index " +
+                              std::to_string(i));
+    }
+
+    update(1, 0, n - 1, i, t);
+  }
+
+ private:
+  inline T const sentinel() const noexcept {
+    return MAX<T>;
+  }
+
+  inline T const merge(T const& x, T const& y) const noexcept {
+    return min(x, y);
+  }
+
+  void build(size_t const node, size_t const l, size_t const r,
+             std::vector<T> const& ts) noexcept {
+    if (l == r) {
+      tree[node] = ts[l];
+    } else {
+      int m = l + (r - l) / 2;
+      build(2 * node, l, m, ts);
+      build(2 * node + 1, m + 1, r, ts);
+      tree[node] = merge(tree[2 * node], tree[2 * node + 1]);
+    }
+  }
+
+  [[nodiscard]] T query(size_t const node, size_t const lower,
+                        size_t const upper, size_t const l,
+                        size_t const r) const noexcept {
+    if (upper < l || r < lower) {
+      return sentinel();
+    }
+
+    if (l <= lower && upper <= r) {
+      return tree[node];
+    }
+
+    size_t m = lower + (upper - lower) / 2;
+
+    return merge(query(2 * node, lower, m, l, r),
+                 query(2 * node + 1, m + 1, upper, l, r));
+  }
+
+  void update(size_t const node, size_t const l, size_t const r, size_t const i,
+              T const& t) noexcept {
+    if (l == r) {
+      tree[node] = t;
+    } else {
+      size_t m = l + (r - l) / 2;
+      if (i <= m) {
+        update(2 * node, l, m, i, t);
+      } else {
+        update(2 * node + 1, m + 1, r, i, t);
+      }
+      tree[node] = merge(tree[2 * node], tree[2 * node + 1]);
+    }
+  }
+
+  size_t n;
+  std::vector<T> tree;
+};
+
+void solve() {
+  int n, q;
+  cin >> n >> q;
+  v<ll> a(n);
+  for (auto& e : a) {
+    cin >> e;
+  }
+  segment_tree<ll> st(a);
+
+  while (q--) {
+    char cmd;
+    cin >> cmd;
+    if (cmd == '1') {
+      int i;
+      ll u;
+      cin >> i >> u;
+      --i;
+      st.update(i, u);
+      a[i] = u;
+    } else {
+      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;
+}
+// }}}