Submission #340042

#	Time	Username	Problem	Language	Result	Execution time	Memory
340042		sinamhdv	Commuter Pass (JOI18_commuter_pass)	C++11	100 / 100	470 ms	24024 KiB

commuter_pass

// https://oj.uz/problem/view/JOI18_commuter_pass
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1000 * 1000 * 1000;
const ll LINF = (ll)INF * INF;

#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define msub(a, b) ((mod + ((a) - (b)) % mod) % mod)
#define mdiv(a, b) ((a) * poww((b), mod - 2) % mod)
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define endl '\n'

#define MAXN 200100
#define MAXM 200100

int n, m, s, t, u, v;
vector<int> adj[MAXN];
int efrom[MAXM], eto[MAXM], ew[MAXM];
ll sdist[MAXN], vdist[MAXN], udist[MAXN];
int ver[MAXN];
ll dp[MAXN];
ll udp[MAXN], vdp[MAXN];

priority_queue<pll, vector<pll>, greater<pll>> pq;

inline void dij(int r, ll dist[MAXN])
{
	fill(dist, dist + n + 10, LINF);
	dist[r] = 0;
	FOR(i, 1, n + 1)
	{
		pq.push(mp(dist[i], i));
	}
	while (!pq.empty())
	{
		pll p = pq.top();
		pq.pop();
		int v = p.sc;
		if (p.fr != dist[v])
		{
			continue;
		}
		for (int e : adj[v])
		{
			int u = efrom[e] ^ eto[e] ^ v;
			ll nw = dist[v] + ew[e];
			if (nw < dist[u])
			{
				dist[u] = nw;
				pq.push(mp(dist[u], u));
			}
		}
	}
}

bool cmp(int a, int b)
{
	return sdist[a] < sdist[b];
}

int32_t main(void)
{
	scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
	FOR(i, 0, m)
	{
		int x, y, w;
		scanf("%d%d%d", &x, &y, &w);
		adj[x].pb(i);
		adj[y].pb(i);
		efrom[i] = x;
		eto[i] = y;
		ew[i] = w;
	}
	
	dij(s, sdist);
	dij(u, udist);
	dij(v, vdist);

	iota(ver + 1, ver + n + 1, 1);
	sort(ver + 1, ver + n + 1, cmp);

	FOR(i, 1, n + 1)
	{
		int x = ver[i];
		udp[x] = udist[x];
		vdp[x] = vdist[x];
		dp[x] = vdist[x] + udist[x];
		for (int e : adj[x])
		{
			int y = efrom[e] ^ eto[e] ^ x;
			if (sdist[y] + ew[e] == sdist[x])
			{
				udp[x] = min(udp[x], udp[y]);
				vdp[x] = min(vdp[x], vdp[y]);
				dp[x] = min(dp[x], dp[y]);
				dp[x] = min(dp[x], min(udp[y] + vdist[x], vdp[y] + udist[x]));
			}
		}
	}

	ll ans = udist[v];
	ans = min(ans, dp[t]);

	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int32_t main()':
commuter_pass.cpp:80:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   80 |  scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:84:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   84 |   scanf("%d%d%d", &x, &y, &w);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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