feat(codeforces/1020): a-e

codeforces/1020/d.cc

@@ -0,0 +1,121 @@
+#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 d64 = double;
+using d128 = long double;
+template <typename T>
+using vec = std::vector<T>;
+template <typename T, size_t N>
+using arr = std::array<T, N>;
+template <typename T1, typename T2>
+using pai = std::pair<T1, T2>;
+
+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());
+}
+
+static void NO() {
+  std::cout << "NO\n";
+}
+
+static void YES() {
+  std::cout << "YES\n";
+}
+
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+
+#ifdef LOCAL
+#define db(...) std::print(__VA_ARGS__)
+#define dbln(...) std::println(__VA_ARGS__)
+#else
+#define db(...)
+#define dbln(...)
+#endif
+//  }}}
+
+void solve() {
+  i64 n, m;
+  cin >> n >> m;
+
+  vector<i64> a(n), b(m);
+  for (auto& e : a)
+    cin >> e;
+  for (auto& e : b)
+    cin >> e;
+  a.emplace_back(MIN<i64>);
+
+  i64 ans = MAX<i32>;
+
+  vec<i64> post(m + 1, -1);
+  post[m] = n;
+
+  i64 i = n - 1;
+  for (i64 j = m - 1; j >= 0 && i >= 0; --j) {
+    while (i >= 0 && a[i] < b[j]) {
+      --i;
+    }
+
+    if (post[j] == -1)
+      post[j] = i;
+    --i;
+  }
+
+  i64 j = 0;
+  i64 matched = 0;
+  for (i = 0; i <= n && j < m; ++i) {
+    if (post[j + 1] >= i) {
+      ans = min(ans, b[j]);
+    }
+
+    if (a[i] >= b[j]) {
+      if (++matched == m) {
+        ans = 0;
+        break;
+      }
+      ++j;
+    }
+  }
+
+  if (ans == MAX<i32>)
+    cout << "-1\n";
+  else
+    cout << ans << '\n';
+}
+
+int main() {  // {{{
+  cin.tie(nullptr)->sync_with_stdio(false);
+  cin.exceptions(cin.failbit);
+
+  int tc = 1;
+  cin >> tc;
+
+  for (int t = 0; t < tc; ++t) {
+    solve();
+  }
+
+  return 0;
+}
+// }}}