| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1182693 | Zbyszek99 | Olympic Bus (JOI20_ho_t4) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ff first
#define ss second
#define vl vector<long long>
#define vi vector<int>
#define pii pair<int,int>
#define pll pair<long long, long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
//mt19937 mt;void random(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll rand(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
pii edge[50001];
ll cost[50001];
ll swap_cost[50001];
vector<pii> dij_graph[201];
ll ans = 1e18;
ll dist[50001][6];
pii nxt[50001];
int n,m;
void dij(int start, int type)
{
vi mam;
mam.pb(start);
vi nie_mam;
rep2(i,1,n) if(i != start) nie_mam.pb(i);
rep2(i,1,n) dist[i][type] = 1e18;
rep2(i,1,n) nxt[i] = 0;
dist[start][type] = 0;
rep(i,n-1)
{
// cout << i << " " << start << " " << type << " " << siz(mam) << " iter\n";
pair<pll,pii> best = {{1e18,1},{1,1}};
forall(it,mam)
{
// cout << it << " mam\n";
forall(e,dij_graph[it])
{
// cout << e.ff << " " << e.ss << " edges\n";
if(dist[e.ff][type] != 1e18) continue;
best = min(best,{{dist[it][type] + cost[e.ss],it},{e.ff,e.ss}});
}
}
// cout << best.ff.ff << " " << best.ff.ss << " " << best.ss.ff << " " << best.ss.ss << " best\n";
if(best.ff.ff == 1e18) break;
dist[best.ss.ff][type] = best.ff.ff;
nxt[best.ss.ff] = {best.ff.ss,best.ss.ss};
mam.pb(best.ss.ff);
rep(i,siz(nie_mam))
{
if(nie_mam[i] == best.ss.ff)
{
swap(nie_mam[i],nie_mam[siz(nie_mam)-1]);
nie_mam.pop_back();
break;
}
}
}
}
void solve(int s, int t)
{
rep2(i,1,n) dij_graph[i] = {};
rep(i,m)
{
dij_graph[edge[i].ss].pb({edge[i].ff,i});
}
dij(t,1);
dij(s,5);
rep2(i,1,n) dij_graph[i] = {};
rep(i,m)
{
dij_graph[edge[i].ff].pb({edge[i].ss,i});
}
dij(s,0);
dij(t,4);
ans = min(ans,dist[s][4] + dist[t][0]);
vi path;
set<int> path_set;
int cur = s;
while(cur != t && cur != 0)
{
path.pb(nxt[cur].ss);
path_set.insert(nxt[cur].ss);
cur = nxt[cur].ff;
}
//forall(it,path) cout << it << " path\n";
//cout << "\n";
rep(i,m)
{
if(path_set.find(i) == path_set.end())
{
ans = min(ans,swap_cost[i] + dist[edge[i].ss][0] + dist[edge[i].ff][1] + cost[i] + min(dist[s][4],dist[edge[i].ss][4] + cost[i] + dist[edge[i].ff][5]));
// cout << i << " " << edge[i].ff << " " << edge[i].ss << " " << ans << " " << dist[edge[i].ss][0] << " " << dist[edge[i].ff][1] << " " << cost[i] << " " << min(dist[s][4],dist[edge[i].ss][1] + cost[i] + dist[edge[i].ff][0])<< " not_path_edge\n";
}
else
{
swap(edge[i].ff,edge[i].ss);
rep2(j,1,n) dij_graph[j] = {};
rep(j,m)
{
dij_graph[edge[i].ff].pb({edge[i].ss,i});
}
dij(s,2);
rep2(j,1,n) dij_graph[j] = {};
rep(j,m)
{
dij_graph[edge[i].ff].pb({edge[i].ss,i});
}
dij(t,3);
swap(edge[i].ff,edge[i].ss);
ans = min(ans,dist[t][2] + dist[s][3] + swap_cost[i]);
// cout << i << " " << ans << " path_edge\n";
}
}
//cout << "\n\n";
}
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//random();
cin >> n >> m;
rep(i,m)
{
int a,b;
cin >> a >> b >> cost[i] >> swap_cost[i];
edge[i] = {a,b};
}
solve(1,n);
solve(n,1);
if(ans != 1e18)
{
cout << ans << "\n";
}
else cout << "-1\n";
}