提出 #64760216

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ソースコード 拡げる

#ifndef ATCODER_DSU_HPP
#define ATCODER_DSU_HPP 1

#include <algorithm>
#include <cassert>
#include <vector>

namespace atcoder {

// Implement (union by size) + (path compression)
// Reference:
// Zvi Galil and Giuseppe F. Italiano,
// Data structures and algorithms for disjoint set union problems
struct dsu {
 public:
  dsu() : _n(0) {}
  explicit dsu(int n) : _n(n), parent_or_size(n, -1) {}

  int merge(int a, int b) {
    assert(0 <= a && a < _n);
    assert(0 <= b && b < _n);
    int x = leader(a), y = leader(b);
    if (x == y) return x;
    if (-parent_or_size[x] < -parent_or_size[y]) std::swap(x, y);
    parent_or_size[x] += parent_or_size[y];
    parent_or_size[y] = x;
    return x;
  }

  bool same(int a, int b) {
    assert(0 <= a && a < _n);
    assert(0 <= b && b < _n);
    return leader(a) == leader(b);
  }

  int leader(int a) {
    assert(0 <= a && a < _n);
    if (parent_or_size[a] < 0) return a;
    return parent_or_size[a] = leader(parent_or_size[a]);
  }

  int size(int a) {
    assert(0 <= a && a < _n);
    return -parent_or_size[leader(a)];
  }

  std::vector<std::vector<int>> groups() {
    std::vector<int> leader_buf(_n), group_size(_n);
    for (int i = 0; i < _n; i++) {
      leader_buf[i] = leader(i);
      group_size[leader_buf[i]]++;
    }
    std::vector<std::vector<int>> result(_n);
    for (int i = 0; i < _n; i++) {
      result[i].reserve(group_size[i]);
    }
    for (int i = 0; i < _n; i++) {
      result[leader_buf[i]].push_back(i);
    }
    result.erase(
        std::remove_if(result.begin(), result.end(),
                       [&](const std::vector<int>& v) { return v.empty(); }),
        result.end());
    return result;
  }

 private:
  int _n;
  // root node: -1 * component size
  // otherwise: parent
  std::vector<int> parent_or_size;
};

}  // namespace atcoder

#endif  // ATCODER_DSU_HPP

#ifndef IO_HPP
#define IO_HPP 1

#include <array>
#include <cstdint>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

namespace io {

void __read(char& c) { std::cin >> c; }
void __read(std::string& s) { std::cin >> s; }

template <typename T>
void __read_real(T& x) {
  std::string s;
  __read(s);
  x = std::stod(s);
}

template <typename T>
void __read_integer(T& x) {
  std::cin >> x;
}

void __read(int& x) { __read_integer(x); }
void __read(unsigned int& x) { __read_integer(x); }
void __read(long& x) { __read_integer(x); }
void __read(unsigned long& x) { __read_integer(x); }
void __read(long long& x) { __read_integer(x); }
void __read(unsigned long long& x) { __read_integer(x); }
void __read(double& x) { __read_real(x); }
void __read(long double& x) { __read_real(x); }

template <class U, class V>
void __read(std::pair<U, V>& p) {
  __read(p.first);
  __read(p.second);
}

template <size_t N = 0, typename T>
void __read_tuple(T& t) {
  if constexpr (N < std::tuple_size<T>::value) {
    auto& x = std::get<N>(t);
    __read(x);
    __read_tuple<N + 1>(t);
  }
}
template <class... T>
void __read(std::tuple<T...>& t) {
  __read_tuple(t);
}

template <size_t N = 0, typename T>
void __read(std::array<T, N>& a) {
  for (auto& x : a) {
    __read(x);
  }
}

template <class T>
void __read(std::vector<T>& v) {
  for (auto& x : v) {
    __read(x);
  }
}

void read() {}
template <class H, class... T>
void read(H& h, T&... t) {
  __read(h), read(t...);
}

void __write(const char c) { std::cout << c; }

void __write(const std::string s) {
  for (char c : s) {
    __write(c);
  }
}

void __write(const char* s) {
  size_t len = strlen(s);
  for (size_t i = 0; i < len; ++i) {
    __write(s[i]);
  }
}

template <typename T>
void __write_integer(T x) {
  std::cout << x;
}

template <typename T>
void __write_real(T x) {
  std::ostringstream oss;
  oss << std::fixed << std::setprecision(15) << double(x);
  std::string s = oss.str();
  __write(s);
}

void __write(int x) { __write_integer(x); }
void __write(unsigned int x) { __write_integer(x); }
void __write(long x) { __write_integer(x); }
void __write(unsigned long x) { __write_integer(x); }
void __write(long long x) { __write_integer(x); }
void __write(unsigned long long x) { __write_integer(x); }
void __write(double x) { __write_real(x); }
void __write(long double x) { __write_real(x); }

template <class U, class V>
void __write(const std::pair<U, V> p) {
  __write(p.first);
  __write(' ');
  __write(p.second);
}

template <size_t N = 0, typename T>
void __write_tuple(const T t) {
  if constexpr (N < std::tuple_size<T>::value) {
    if constexpr (N > 0) {
      __write(' ');
    }
    const auto x = std::get<N>(t);
    __write(x);
    __write_tuple<N + 1>(t);
  }
}
template <class... T>
void __write(std::tuple<T...> t) {
  __write_tuple(t);
}

template <class T, size_t S>
void __write(const std::array<T, S> a) {
  auto n = a.size();
  for (size_t i = 0; i < n; i++) {
    if (i) {
      __write(' ');
    }
    __write(a[i]);
  }
}

template <class T>
void __write(const std::vector<T> v) {
  auto n = v.size();
  for (size_t i = 0; i < n; i++) {
    if (i) {
      __write(' ');
    }
    __write(v[i]);
  }
}

template <class T>
void __write(const std::set<T> s) {
  __write(std::vector<T>{s.cbegin(), s.cend()});
}

template <class K, class V>
void __write(const std::map<K, V> m) {
  __write(std::vector<std::pair<K, V>>{m.cbegin(), m.cend()});
}

void write() { __write('\n'); }
template <class Head, class... Tail>
void write(Head&& head, Tail&&... tail) {
  __write(head);
  if (sizeof...(Tail)) {
    __write(' ');
  }
  write(std::forward<Tail>(tail)...);
}

}  // namespace io

#endif  // IO_HPP

#ifdef ONLINE_JUDGE
#include <bits/allocator.h>
#pragma GCC optimize("Ofast,unroll-loops,inline")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#endif

#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
using namespace atcoder;
using namespace io;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

void solve() {
  int n, m;
  read(n, m);
  vector<pair<int, int>> uv(m);
  read(uv);
  vector<vector<int>> g(n);
  for (auto& [u, v] : uv) {
    --u, --v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  int k{};
  set<int> op;
  dsu cc(n);
  for (int u{}; u < n; ++u) {
    ++k;
    op.erase(u);
    for (int v : g[u]) {
      if (u < v) {
        op.insert(v);
      } else {
        k -= !cc.same(u, v);
        cc.merge(u, v);
      }
    }
    write(k > 1 ? -1 : int{op.size()});
  }
}

int main() {
  cin.tie(0)->sync_with_stdio(0);
  solve();
}

提出情報

コンパイルエラー

Main.cpp: In function ‘void solve()’:
Main.cpp:310:35: warning: narrowing conversion of ‘op.std::set<int>::size()’ from ‘std::set<int>::size_type’ {aka ‘long unsigned int’} to ‘int’ [-Wnarrowing]
  310 |     write(k > 1 ? -1 : int{op.size()});
      |                            ~~~~~~~^~
Main.cpp:310:35: warning: narrowing conversion of ‘op.std::set<int>::size()’ from ‘std::set<int>::size_type’ {aka ‘long unsigned int’} to ‘int’ [-Wnarrowing]

ジャッジ結果