結果
| 問題 |
No.848 なかよし旅行
|
| コンテスト | |
| ユーザー |
 Pachicobue
|
| 提出日時 | 2019-07-06 21:46:57 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 143 ms / 2,000 ms |
| コード長 | 7,920 bytes |
| コンパイル時間 | 1,972 ms |
| コンパイル使用メモリ | 206,284 KB |
| 最終ジャッジ日時 | 2025-01-07 06:24:58 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge4 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 4 |
| other | AC * 26 |
ソースコード
#include <bits/stdc++.h>
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"
#define NDEBUG
#define SHOW(...) static_cast<void>(0)
//!===========================================================!//
//! dP dP dP !//
//! 88 88 88 !//
//! 88aaaaa88a .d8888b. .d8888b. .d888b88 .d8888b. 88d888b. !//
//! 88 88 88ooood8 88' '88 88' '88 88ooood8 88' '88 !//
//! 88 88 88. ... 88. .88 88. .88 88. ... 88 !//
//! dP dP '88888P' '88888P8 '88888P8 '88888P' dP !//
//!===========================================================!//
template <typename T>
T read()
{
T v;
return std::cin >> v, v;
}
template <typename T>
std::vector<T> readVec(const std::size_t l)
{
std::vector<T> v(l);
for (auto& e : v) { std::cin >> e; }
return v;
}
using ld = long double;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr unsigned int MOD = 1000000007;
template <typename T>
constexpr T INF = std::numeric_limits<T>::max() / 4;
template <typename F>
constexpr F PI = static_cast<F>(3.1415926535897932385);
std::mt19937 mt{std::random_device{}()};
template <typename T>
bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template <typename T>
bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
template <typename T>
std::vector<T> Vec(const std::size_t n, T v) { return std::vector<T>(n, v); }
template <class... Args>
auto Vec(const std::size_t n, Args... args) { return std::vector<decltype(Vec(args...))>(n, Vec(args...)); }
template <typename T>
constexpr T popCount(const T u)
{
#ifdef __has_builtin
return u == 0 ? T(0) : (T)__builtin_popcountll(u);
#else
unsigned long long v = static_cast<unsigned long long>(u);
return v = (v & 0x5555555555555555ULL) + (v >> 1 & 0x5555555555555555ULL), v = (v & 0x3333333333333333ULL) + (v >> 2 & 0x3333333333333333ULL), v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL, static_cast<T>(v * 0x0101010101010101ULL >> 56 & 0x7f);
#endif
}
template <typename T>
constexpr T log2p1(const T u)
{
#ifdef __has_builtin
return u == 0 ? T(0) : T(64 - __builtin_clzll(u));
#else
unsigned long long v = static_cast<unsigned long long>(u);
return v = static_cast<unsigned long long>(v), v |= (v >> 1), v |= (v >> 2), v |= (v >> 4), v |= (v >> 8), v |= (v >> 16), v |= (v >> 32), popCount(v);
#endif
}
template <typename T>
constexpr T clog(const T v) { return v == 0 ? T(0) : log2p1(v - 1); }
template <typename T>
constexpr T msbp1(const T v) { return log2p1(v); }
template <typename T>
constexpr T lsbp1(const T v)
{
#ifdef __has_builtin
return __builtin_ffsll(v);
#else
return v == 0 ? T(0) : popCount((v & (-v)) - T(1)) + T(1);
#endif
}
template <typename T>
constexpr bool ispow2(const T v) { return popCount(v) == 1; }
template <typename T>
constexpr T ceil2(const T v) { return v == 0 ? T(1) : T(1) << log2p1(v - 1); }
template <typename T>
constexpr T floor2(const T v) { return v == 0 ? T(0) : T(1) << (log2p1(v) - 1); }
//!=======================================================================================!//
//! a88888b. dP .88888. dP !//
//! d8' '88 88 d8' '88 88 !//
//! 88 .d8888b. .d8888b. d8888P 88 88d888b. .d8888b. 88d888b. 88d888b. !//
//! 88 88' '88 Y8ooooo. 88 88 YP88 88' '88 88' '88 88' '88 88' '88 !//
//! Y8. .88 88. .88 88 88 Y8. .88 88 88. .88 88. .88 88 88 !//
//! Y88888P' '88888P' '88888P' dP '88888' dP '88888P8 88Y888P' dP dP !//
//! 88 !//
//! dP !//
//!=======================================================================================!//
template <typename Cost>
struct CostGraph
{
CostGraph(const std::size_t v) : V{v}, edge(v), rev_edge(v) {}
void addEdge(const std::size_t from, const std::size_t to, const Cost cost, const bool bi = false)
{
assert(from < V), assert(to < V);
edge[from].push_back(Edge{to, cost}), rev_edge[to].push_back(Edge(from, cost));
if (bi) { addEdge(to, from, cost, false); }
}
struct Edge
{
Edge(const std::size_t to, const Cost cost) : to{to}, cost{cost} {}
const std::size_t to;
const Cost cost;
bool operator<(const Edge& e) const { return cost != e.cost ? cost < e.cost : to < e.to; }
};
const std::vector<Edge>& operator[](const std::size_t i) const { return assert(i < V), edge[i]; }
friend std::ostream& operator<<(std::ostream& os, const CostGraph& g)
{
os << "[\n";
for (std::size_t i = 0; i < g.V; i++) {
for (const auto& e : g.edge[i]) { os << i << "->" << e.to << ":" << e.cost << "\n"; }
}
return (os << "]\n");
}
const std::size_t V;
std::vector<std::vector<Edge>> edge, rev_edge;
};
template <typename Cost>
using CostTree = CostGraph<Cost>;
//!==============================================================!//
//! 888888ba oo oo dP dP !//
//! 88 '8b 88 88 !//
//! 88 88 dP dP 88 .dP .d8888b. d8888P 88d888b. .d8888b. !//
//! 88 88 88 88 88888" Y8ooooo. 88 88' '88 88' '88 !//
//! 88 .8P 88 88 88 '8b. 88 88 88 88. .88 !//
//! 8888888P dP 88 dP 'YP '88888P' dP dP '88888P8 !//
//! 88 !//
//! dP !//
//!==============================================================!//
template <typename Cost>
std::vector<Cost> Dijkstra(const CostGraph<Cost>& g, const std::size_t s)
{
std::vector<Cost> d(g.V, std::numeric_limits<Cost>::max());
using P = std::pair<Cost, std::size_t>;
std::priority_queue<P, std::vector<P>, std::greater<P>> q;
d[s] = 0, q.push({0, s});
while (not q.empty()) {
const Cost cost = q.top().first;
const std::size_t v = q.top().second;
q.pop();
if (d[v] < cost) { continue; }
for (const auto& e : g.edge[v]) {
if (d[e.to] <= d[v] + e.cost) { continue; }
d[e.to] = d[v] + e.cost, q.push({d[e.to], e.to});
}
}
return d;
}
//!=====================================!//
//! 8888ba.88ba oo !//
//! 88 '8b '8b !//
//! 88 88 88 .d8888b. dP 88d888b. !//
//! 88 88 88 88' '88 88 88' '88 !//
//! 88 88 88 88. .88 88 88 88 !//
//! dP dP dP '88888P8 dP dP dP !//
//!=====================================!//
int main()
{
const int N = read<int>(), M = read<int>(), P = read<int>() - 1, Q = read<int>() - 1;
const ll T = read<ll>();
CostGraph<ll> G(N);
for (int i = 0; i < M; i++) {
const int a = read<int>() - 1, b = read<int>() - 1;
const ll c = read<ll>();
G.addEdge(a, b, c, true);
}
const auto D1 = Dijkstra(G, 0);
const auto D2 = Dijkstra(G, P);
const auto D3 = Dijkstra(G, Q);
if (D1[P] + D2[Q] + D3[0] <= T) {
std::cout << T << std::endl;
} else {
ll ans = -1;
for (std::size_t i = 0; i < N; i++) {
for (std::size_t j = 0; j < N; j++) {
const ll common = D1[i] + D1[j];
const ll a = D2[i] + D2[j], b = D3[i] + D3[j];
if (common + a <= T and common + b <= T) { chmax(ans, T - std::max(a, b)); }
}
}
std::cout << ans << std::endl;
}
return 0;
}