Submission #530710

#	Time	Username	Problem	Language	Result	Execution time	Memory
530710		Bungmint	Commuter Pass (JOI18_commuter_pass)	C++17	31 / 100	343 ms	18612 KiB

commuter_pass

//Copyright © 2021 Youngmin Park. All rights reserved.
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;

#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define REP(a) F0R(_, a)

const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7; //998244353;
const ld PI = acos((ld)-1.0);
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }

template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p)
{
    return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v)
{
    os << '{';
    string sep;
    for (const T &x : v)
        os << sep << x, sep = ", ";
    return os << '}';
}
void dbg_out()
{
    cerr << endl;
}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T)
{
    cerr << ' ' << H;
    dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif

inline namespace RecursiveLambda{
	template <typename Fun>
	struct y_combinator_result{
		Fun fun_;
		template <typename T> 
		explicit y_combinator_result(T &&fun): fun_(forward<T>(fun)){}
		template <typename...Args>
		decltype(auto) operator()(Args &&...args){
			return fun_(ref(*this), forward<Args>(args)...);
		}
	};
	template <typename Fun>
	decltype(auto) y_combinator(Fun &&fun){
		return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
	}
};

void setIO(string s) // USACO
{
	#ifndef LOCAL
	    freopen((s + ".in").c_str(), "r", stdin);
	    freopen((s + ".out").c_str(), "w", stdout);
	#endif
}

const int N = 1e5 + 10;
vpi g[N];
ll distUV[2][N];
ll dist[N], mi[2][N];


void dijkstra(int src, int fl) {
	pqg<pll> pq;
	fill(distUV[fl], distUV[fl] + N, LINF);
	distUV[fl][src] = 0;
	pq.push({0, src});
	while (sz(pq)) {
		auto [d, u] = pq.top();
		pq.pop();
		dbg(distUV[fl][u], fl, u);
		if (distUV[fl][u] < d) continue;
		for (auto &[v, w] : g[u]) {
			if (ckmin(distUV[fl][v], distUV[fl][u] + w)) {
				pq.push({distUV[fl][v], v});
			}
		}
	}
}


ll modDijkstra(int src, int dest) {
	pqg<pll> pq;
	fill(dist, dist + N, LINF);
	F0R(i, 2) fill(mi[i], mi[i] + N, LINF);
	pq.push({0, src});
	dist[src] = 0;
	mi[0][src] = distUV[0][src];
	mi[1][src] = distUV[1][src];
	dbg(distUV[1][src]);
	while (sz(pq)) {
		auto [d, u] = pq.top();
		pq.pop();
		if (dist[u] < d) continue;
		for (auto &[v, w] : g[u]) {
			if (ckmin(dist[v], dist[u] + w)) {
				pq.push({dist[v], v});
				mi[0][v] = min(mi[0][u], distUV[0][v]);
				mi[1][v] = min(mi[1][u], distUV[1][v]);
			}else if (dist[v] == dist[u] + w) {
				ckmin(mi[0][v], mi[0][u]);
				ckmin(mi[1][v], mi[1][u]);
			}
		}
	}
	return mi[0][dest] + mi[1][dest];
}


void solve()
{
	int n, m, u, v, s, t;
	cin >> n >> m;
	cin >> s >> t >> u >> v;
	s--, t--, u--, v--;
	REP(m) {
		int a, b, c;
		cin >> a >> b >> c;
		a--, b--;
		g[a].pb({b, c});
		g[b].pb({a, c});
	}
	dijkstra(u, 0);
	dijkstra(v, 1);
	cout << min({modDijkstra(s, t), modDijkstra(t, s), distUV[0][v]}) << "\n";
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int testcase=1;
    // cin >> testcase;
    while (testcase--)
    {
        solve();
    }
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dijkstra(int, int)':
commuter_pass.cpp:71:18: warning: statement has no effect [-Wunused-value]
   71 | #define dbg(...) 42
      |                  ^~
commuter_pass.cpp:113:3: note: in expansion of macro 'dbg'
  113 |   dbg(distUV[fl][u], fl, u);
      |   ^~~
commuter_pass.cpp: In function 'll modDijkstra(int, int)':
commuter_pass.cpp:71:18: warning: statement has no effect [-Wunused-value]
   71 | #define dbg(...) 42
      |                  ^~
commuter_pass.cpp:132:2: note: in expansion of macro 'dbg'
  132 |  dbg(distUV[1][src]);
      |  ^~~
commuter_pass.cpp: In function 'void setIO(std::string)':
commuter_pass.cpp:94:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |      freopen((s + ".in").c_str(), "r", stdin);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:95:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |      freopen((s + ".out").c_str(), "w", stdout);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45