Submission #581179

#	Time	Username	Problem	Language	Result	Execution time	Memory
581179		Theo830	Robot (JOI21_ho_t4)	C++17	0 / 100	371 ms	87796 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18+7;
const ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ll,ii>
#define ull unsigned ll
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
vector<vector<ii> >adj;
vector<vector<iii> >exo;
vector<ll> dist;
void dijkstra(ll s){
    priority_queue<ii,vector<ii>, greater<ii> >pq;
    pq.push(ii(0,s));
    dist[s] = 0;
    while(!pq.empty()){
        ii f = pq.top();
        pq.pop();
        ll w = f.F;
        ll u = f.S;
        if(w > dist[u]){
            continue;
        }
        for(auto v:adj[u]){
            if(dist[u] + v.S < dist[v.F]){
                dist[v.F] = dist[u] + v.S;
                pq.push(ii(dist[v.F],v.F));
            }
        }
    }
}
int main(void){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n,m;
    cin>>n>>m;
    ll siz = 2 * (n + m + 5);
    adj.assign(siz,vector<ii>());
    exo.assign(siz,vector<iii>());
    dist.assign(siz,1e18);
    ll fake = n+5;
    f(i,0,m){
        ll a,b,c,d;
        cin>>a>>b>>c>>d;
        adj[a].pb(ii(b,d));
        adj[b].pb(ii(a,d));
        exo[a].pb(iii(b,ii(c,d)));
        exo[b].pb(iii(a,ii(c,d)));
    }
    ll sum[m+1] = {0};
    ll xroma[m+1] = {0};
    f(i,1,n+1){
        for(auto x:exo[i]){
            sum[x.S.F] += x.S.S;
            if(!xroma[x.S.F]){
                xroma[x.S.F] = fake;
                fake++;
            }
        }
        for(auto x:exo[i]){
            adj[i].pb(ii(x.F,sum[x.S.F] - x.S.S));
            adj[x.F].pb(ii(xroma[x.S.F],sum[x.S.F]));
            //adj[xroma[x.S.F]].pb(ii(x.F,-x.S.S));
        }
        for(auto x:exo[i]){
            sum[x.S.F] -= x.S.S;
            xroma[x.S.F] = 0;
        }
    }
    dijkstra(1);
    if(dist[n] == 1e18){
        dist[n] = -1;
    }
    cout<<dist[n]<<"\n";
}

• Subtask 1: 0 / 34
• Subtask 2: 0 / 24
• Subtask 3: 0 / 42