Submission #19330997


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// #define LOCAL
#define _USE_MATH_DEFINES
#include <array>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>
#include <functional>
#include <random>
#include <ctime>

using namespace std;

template <typename A, typename B>
ostream& operator <<(ostream& out, const pair<A, B>& a) {
  out << "(" << a.first << "," << a.second << ")";
  return out;
}
template <typename T, size_t N>
ostream& operator <<(ostream& out, const array<T, N>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const vector<T>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const set<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator <<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& p : a) { out << (first ? "" : ", "); out << p.first << ":" << p.second; first = 0;} out << "}";
  return out;
}
#ifdef LOCAL
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
#else
#define trace(...) 42
#endif
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

typedef long long int64;
typedef pair<int, int> ii;
#define SZ(x) (int)((x).size())
template <typename T> static constexpr T inf = numeric_limits<T>::max() / 2;
const int MOD = 1e9 + 7;
mt19937 mrand(random_device{}());
int rnd(int x) { return mrand() % x; }

struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
  };
} fast_ios_;

int main() {
  int n, m;
  cin >> n >> m;
  vector<int> c(n);
  for (int i = 0; i < n; ++i) cin >> c[i];
  vector<vector<int>> a(n);
  for (int i = 0; i < m; ++i) {
    int x, y;
    cin >> x >> y;
    --x; --y;
    a[x].push_back(y);
  }

  vector<int> dfn(n), low(n), scc(n), S;
  vector<bool> instack(n);
  int stamp = 1;
  function<void(int)> DFS =
    [&](int u) -> void {
      low[u] = dfn[u] = stamp++;
      S.push_back(u);
      instack[u] = true;
      for (auto& v : a[u]) {
        if (dfn[v] == 0) {
          DFS(v);
          low[u] = min(low[u], low[v]);
        } else if (instack[v]) {
          low[u] = min(low[u], dfn[v]);
        }
      }
      if (low[u] == dfn[u]) {
        while (true) {
          int v = S.back();
          scc[v] = u;
          instack[v] = false;
          S.pop_back();
          if (v == u) break;
        }
      }
    };
  for (int i = 0; i < n; ++i) {
    if (!dfn[i]) DFS(i);
  }

  vector<int> C(n, inf<int>);
  for (int i = 0; i < n; ++i) {
    int j = scc[i];
    C[j] = min(C[j], c[i]);
  }

  vector<vector<int>> b(n);
  for (int i = 0; i < n; ++i) {
    int u = scc[i];
    for (auto& j : a[i]) {
      int v = scc[j];
      b[u].push_back(v);
      trace(u, v);
    }
  }

  vector<int> dp(n, -inf<int>), best(n);
  function<int(int)> solve =
    [&](int u) {
      if (best[u]) return best[u];
      best[u] = C[u];
      for (auto& v : b[u]) {
        int cur = solve(v);
        best[u] = max(best[u], cur);
        dp[u] = max(dp[u], cur - C[u]);
      }
      return best[u];
    };

  int ret = -inf<int>;
  for (int i = 0; i < n; ++i) {
    if (scc[i] != i) continue;
    solve(i);
    ret = max(ret, dp[i]);
  }
  cout << ret << '\n';

  return 0;
}

Submission Info

Submission Time
Task E - Peddler
User cuiaoxiang
Language C++ (Clang 10.0.0)
Score 500
Code Size 4340 Byte
Status AC
Exec Time 428 ms
Memory 46628 KB

Compile Error

./Main.cpp:79:11: warning: unused variable 'MOD' [-Wunused-const-variable]
const int MOD = 1e9 + 7;
          ^
1 warning generated.

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 500 / 500
Status
AC × 3
AC × 49
Set Name Test Cases
Sample sample_01.txt, sample_02.txt, sample_03.txt
All extreme_00.txt, extreme_01.txt, extreme_02.txt, extreme_03.txt, handmade_00.txt, handmade_01.txt, random_00.txt, random_01.txt, random_02.txt, random_03.txt, random_04.txt, random_05.txt, random_06.txt, random_07.txt, random_08.txt, random_09.txt, random_10.txt, random_11.txt, random_12.txt, random_13.txt, random_14.txt, random_15.txt, random_16.txt, random_17.txt, random_18.txt, random_19.txt, random_dense_00.txt, random_dense_01.txt, random_dense_02.txt, random_dense_03.txt, random_dense_04.txt, random_dense_05.txt, random_dense_06.txt, random_dense_07.txt, random_dense_08.txt, random_dense_09.txt, random_small_00.txt, random_small_01.txt, random_small_02.txt, random_small_03.txt, random_small_04.txt, random_small_05.txt, random_small_06.txt, random_small_07.txt, random_small_08.txt, random_small_09.txt, sample_01.txt, sample_02.txt, sample_03.txt
Case Name Status Exec Time Memory
extreme_00.txt AC 428 ms 46628 KB
extreme_01.txt AC 327 ms 19400 KB
extreme_02.txt AC 355 ms 24748 KB
extreme_03.txt AC 165 ms 17416 KB
handmade_00.txt AC 3 ms 3060 KB
handmade_01.txt AC 2 ms 3120 KB
random_00.txt AC 272 ms 19876 KB
random_01.txt AC 313 ms 17220 KB
random_02.txt AC 157 ms 5380 KB
random_03.txt AC 196 ms 11472 KB
random_04.txt AC 133 ms 5124 KB
random_05.txt AC 137 ms 14952 KB
random_06.txt AC 44 ms 3804 KB
random_07.txt AC 200 ms 15536 KB
random_08.txt AC 238 ms 9316 KB
random_09.txt AC 211 ms 19336 KB
random_10.txt AC 105 ms 7604 KB
random_11.txt AC 299 ms 19908 KB
random_12.txt AC 155 ms 13272 KB
random_13.txt AC 289 ms 21756 KB
random_14.txt AC 170 ms 11468 KB
random_15.txt AC 337 ms 20440 KB
random_16.txt AC 182 ms 11164 KB
random_17.txt AC 346 ms 22812 KB
random_18.txt AC 45 ms 5800 KB
random_19.txt AC 223 ms 19476 KB
random_dense_00.txt AC 80 ms 4260 KB
random_dense_01.txt AC 145 ms 5132 KB
random_dense_02.txt AC 137 ms 4912 KB
random_dense_03.txt AC 118 ms 4608 KB
random_dense_04.txt AC 3 ms 3176 KB
random_dense_05.txt AC 49 ms 3636 KB
random_dense_06.txt AC 143 ms 5068 KB
random_dense_07.txt AC 14 ms 3204 KB
random_dense_08.txt AC 154 ms 5400 KB
random_dense_09.txt AC 45 ms 3724 KB
random_small_00.txt AC 2 ms 3124 KB
random_small_01.txt AC 2 ms 3140 KB
random_small_02.txt AC 2 ms 3128 KB
random_small_03.txt AC 2 ms 2992 KB
random_small_04.txt AC 2 ms 3128 KB
random_small_05.txt AC 2 ms 3000 KB
random_small_06.txt AC 2 ms 3052 KB
random_small_07.txt AC 2 ms 2988 KB
random_small_08.txt AC 2 ms 3056 KB
random_small_09.txt AC 2 ms 3128 KB
sample_01.txt AC 2 ms 3008 KB
sample_02.txt AC 2 ms 3072 KB
sample_03.txt AC 2 ms 3000 KB