Submission #1136950

#	Time	Username	Problem	Language	Result	Execution time	Memory
1136950		pan	Olympic Bus (JOI20_ho_t4)	C++20	0 / 100	1 ms	648 KiB

ho_t4

#include <bits/stdc++.h>
//#include "includeall.h"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define input(x) scanf("%lld", &x);
#define input2(x, y) scanf("%lld%lld", &x, &y);
#define input3(x, y, z) scanf("%lld%lld%lld", &x, &y, &z);
#define input4(x, y, z, a) scanf("%lld%lld%lld%lld", &x, &y, &z, &a);
#define print(x, y) printf("%lld%c", x, y);
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
#define all(x) x.begin(), x.end()
#define discretize(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define FOR(i, x, n) for (ll i =x; i<=n; ++i) 
#define RFOR(i, x, n) for (ll i =x; i>=n; --i) 
using namespace std;
mt19937_64 rnd(chrono::steady_clock::now().time_since_epoch().count());
//using namespace __gnu_pbds;
//#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
//#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
typedef long long ll;
typedef long double ld;
typedef pair<ld, ll> pd;
typedef pair<string, ll> psl;
typedef pair<ll, ll> pi;
typedef pair<pi, ll> pii;
typedef pair<pi, pi> piii;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll INF = 1e15;
ll n, m;
ll u[205], v[205], c[205], d[205];
vector<ll> adj[205];
ll dist[205][205];

void dijkstra(ll from)
{
	fill(dist[from], dist[from] + n + 1, INF);
	dist[from][from] = 0;
	priority_queue<pi, vector<pi>, greater<pi> > pq;
	pq.push(mp(0, from));
	while (pq.size())
	{
		ll now = pq.top().s, dis = pq.top().f;
		pq.pop();
		if (dist[from][now] < dis) continue;
		for (ll x: adj[now]) if (u[x]==now)
		{
			if (dist[from][v[x]] > dis + c[x])
			{
				dist[from][v[x]] = dis + c[x];
				pq.push(mp(dist[from][v[x]] , v[x]));
			}
		}
	}
}

int main()
{
	cin >> n >> m;
	for (ll i=0; i<m; ++i)
	{
		cin >> u[i] >> v[i] >> c[i] >> d[i];
		adj[u[i]].pb(i);
		adj[v[i]].pb(i);
	}
	for (ll i=1; i<=n; ++i) dijkstra(i);
	ll ans = dist[1][n] + dist[n][1];
	//show2(dist[1][n], dist[n][1]);
	for (ll i=0; i<m; ++i)
	{
		if (dist[1][u[i]] + dist[v[i]][n] + c[i] > dist[1][n] && dist[n][u[i]] + dist[v[i]][1] + c[i] > dist[n][1]) // doesn't exist in SP
		{
			ans = min(ans, dist[1][n] + dist[n][v[i]] + dist[u[i]][1] + c[i] +  d[i]);
			ans = min(ans, dist[n][1] + dist[1][v[i]] + dist[u[i]][n] + c[i] +  d[i]);
		}
		else
		{
			swap(u[i], v[i]);
			dijkstra(1);
			dijkstra(n);
			ans = min(ans, dist[1][n] + dist[n][1] + d[i]);
			swap(u[i], v[i]);
			dijkstra(1);
			dijkstra(n);
		}
	}
	if(ans >= INF) cout << -1 << endl;
	else cout << ans << endl;
	return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63