Submission #1182936

#	Time	Username	Problem	Language	Result	Execution time	Memory
1182936		Zbyszek99	Olympic Bus (JOI20_ho_t4)	C++20	37 / 100	1095 ms	2448 KiB

ho_t4

#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] = {0,0};
    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);
    set<int> path_set;
    int cur = t;
    while(cur != s && cur != 0)
    {
        path_set.insert(nxt[cur].ss);
        cur = nxt[cur].ff;
    }
    dij(t,4);
    ans = min(ans,dist[s][4] + dist[t][0]);
    cur = s;
    while(cur != t && cur != 0)
    {
        path_set.insert(nxt[cur].ss);
        cur = nxt[cur].ff;
    }
  //  cout << s << " " << t << " st\n";
  //  forall(it,path_set) 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)
            {
                //cout << edge[i].ff << " "<< edge[i].ss << " edge\n";
                dij_graph[edge[j].ff].pb({edge[j].ss,j});
            }
            dij(s,2);
            rep2(j,1,n) dij_graph[j] = {};
            rep(j,m)
            {
                dij_graph[edge[j].ff].pb({edge[j].ss,j});
            }
            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 << " " << dist[t][2] << " " << dist[s][3] << " 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";
}

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