test/yosupo-judge/kth_root_integer/main.test.cpp

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• Last update: 2021-04-23 23:44:44+09:00
• Problem: https://judge.yosupo.jp/problem/kth_root_integer
• Link: View error logs on GitHub Actions

Depends on

• Input tuple (Mylib/IO/input_tuple.cpp)
• Input tuples (Mylib/IO/input_tuples.cpp)
• Kth root integer (Mylib/Number/kth_root_integer.cpp)

Code

#define PROBLEM "https://judge.yosupo.jp/problem/kth_root_integer"

#include <iostream>
#include "Mylib/IO/input_tuples.cpp"
#include "Mylib/Number/kth_root_integer.cpp"

namespace hl = haar_lib;

int main() {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);

  int T;
  std::cin >> T;

  for (auto [A, K] : hl::input_tuples<uint64_t, uint64_t>(T)) {
    std::cout << hl::kth_root(A, K) << "\n";
  }

  return 0;
}

#line 1 "test/yosupo-judge/kth_root_integer/main.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/kth_root_integer"

#include <iostream>
#line 2 "Mylib/IO/input_tuples.cpp"
#include <initializer_list>
#line 4 "Mylib/IO/input_tuples.cpp"
#include <tuple>
#include <utility>
#include <vector>
#line 6 "Mylib/IO/input_tuple.cpp"

namespace haar_lib {
  template <typename T, size_t... I>
  static void input_tuple_helper(std::istream &s, T &val, std::index_sequence<I...>) {
    (void) std::initializer_list<int>{(void(s >> std::get<I>(val)), 0)...};
  }

  template <typename T, typename U>
  std::istream &operator>>(std::istream &s, std::pair<T, U> &value) {
    s >> value.first >> value.second;
    return s;
  }

  template <typename... Args>
  std::istream &operator>>(std::istream &s, std::tuple<Args...> &value) {
    input_tuple_helper(s, value, std::make_index_sequence<sizeof...(Args)>());
    return s;
  }
}  // namespace haar_lib
#line 8 "Mylib/IO/input_tuples.cpp"

namespace haar_lib {
  template <typename... Args>
  class InputTuples {
    struct iter {
      using value_type = std::tuple<Args...>;
      value_type value;
      bool fetched = false;
      int N, c = 0;

      value_type operator*() {
        if (not fetched) {
          std::cin >> value;
        }
        return value;
      }

      void operator++() {
        ++c;
        fetched = false;
      }

      bool operator!=(iter &) const {
        return c < N;
      }

      iter(int N) : N(N) {}
    };

    int N;

  public:
    InputTuples(int N) : N(N) {}

    iter begin() const { return iter(N); }
    iter end() const { return iter(N); }
  };

  template <typename... Args>
  auto input_tuples(int N) {
    return InputTuples<Args...>(N);
  }
}  // namespace haar_lib
#line 2 "Mylib/Number/kth_root_integer.cpp"
#include <cassert>
#include <cstdint>

namespace haar_lib {
  uint64_t kth_root(uint64_t a, int k) {
    assert(k >= 1);
    if (k == 1) return a;
    if (a == 1) return 1;

    uint64_t lb = 0, ub = a;

    auto check =
        [](uint64_t a, int k, uint64_t n) {
          uint64_t r = 1;

          while (k > 0) {
            if (k & 1) {
              if (__builtin_umulll_overflow(r, a, (unsigned long long int*) &r)) return false;
            }
            if (__builtin_umulll_overflow(a, a, (unsigned long long int*) &a) and k > 1) return false;
            k >>= 1;
          }

          return r <= n;
        };

    while (ub - lb > 1) {
      uint64_t mid = lb + (ub - lb) / 2;

      if (check(mid, k, a)) {
        lb = mid;
      } else {
        ub = mid;
      }
    }

    return lb;
  }
}  // namespace haar_lib
#line 6 "test/yosupo-judge/kth_root_integer/main.test.cpp"

namespace hl = haar_lib;

int main() {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);

  int T;
  std::cin >> T;

  for (auto [A, K] : hl::input_tuples<uint64_t, uint64_t>(T)) {
    std::cout << hl::kth_root(A, K) << "\n";
  }

  return 0;
}

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