Submission #1182954

#	Time	Username	Problem	Language	Result	Execution time	Memory
1182954		Zbyszek99	Olympic Bus (JOI20_ho_t4)	C++20	100 / 100	407 ms	4168 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;

struct e
{
    ll cost;
    int vert,ind;
    bool operator<(const e& o)
    {
        return cost < o.cost;
    }
};

pii edge[50001];
ll cost[50001];
ll swap_cost[50001];
vector<e> dij_graph[201];
ll ans = 1e18;
ll dist[50001][6];
pii nxt[50001];
int sort_ptr[201];
int n,m;

void dij(int start, int type)
{
    rep2(i,1,n) dist[i][type] = 1e18;
    rep2(i,1,n) nxt[i] = {0,0};
    rep2(i,1,n) sort_ptr[i] = 0;
    dist[start][type] = 0;
    rep(i,n-1)
    {
        pair<pll,pii> best = {{1e18,1},{1,1}};
        rep2(j,1,n)
        {
            if(dist[j][type] == 1e18) continue;
            while(sort_ptr[j] < siz(dij_graph[j]))
            {
                if(dij_graph[j][sort_ptr[j]].vert != edge[dij_graph[j][sort_ptr[j]].ind].ss || dist[dij_graph[j][sort_ptr[j]].vert][type] != 1e18)
                {
                    sort_ptr[j]++;
                }
                else break;
            }
            if(sort_ptr[j] < siz(dij_graph[j]))
            {
                if(dij_graph[j][sort_ptr[j]].vert == edge[dij_graph[j][sort_ptr[j]].ind].ss)
                {
                    best = min(best,{{dist[j][type] + dij_graph[j][sort_ptr[j]].cost,j},{dij_graph[j][sort_ptr[j]].vert,dij_graph[j][sort_ptr[j]].ind}});
                }
            }
        }
        if(best.ff.ff == 1e18) break;
       // cout << best.ff.ff << " " << best.ff.ss << " " << " best\n";
        sort_ptr[best.ff.ss]++;
        dist[best.ss.ff][type] = best.ff.ff;
        nxt[best.ss.ff] = {best.ff.ss,best.ss.ss};
    }
   // cout << "\n\ndij_end\n\n";
}

void solve(int s, int t)
{
    rep(i,m)
    {
        swap(edge[i].ff,edge[i].ss);
    }
    dij(t,1);
    dij(s,5);
    rep(i,m)
    {
        swap(edge[i].ff,edge[i].ss);
    }
    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;
    }
    rep(i,m)
    {
        if(path_set.find(i) == path_set.end())
        {
            ans = min(ans,swap_cost[i] + min(dist[t][0],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]));
        }
        else
        {
            swap(edge[i].ff,edge[i].ss);
            dij(s,2);
            dij(t,3);
            swap(edge[i].ff,edge[i].ss);
            ans = min(ans,dist[t][2] + dist[s][3] + swap_cost[i]);
        }
    }
}

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];
        e xd = {cost[i],b,i};
        dij_graph[a].pb(xd);
        xd = {cost[i],a,i};
        dij_graph[b].pb(xd);
        edge[i] = {a,b};
    }
    rep2(i,1,n) sort(all(dij_graph[i]));
    solve(1,n);
    if(ans != 1e18)
    {
        cout << ans << "\n";
    }
    else cout << "-1\n";
}

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