Submission #382668

#	Time	Username	Problem	Language	Result	Execution time	Memory
382668		jainbot27	Robot (JOI21_ho_t4)	C++17	0 / 100	698 ms	32656 KiB

Main

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define F0R(i, n) for(int i=0; i<n; i++)
#define FOR(i, a, b) for(int i=a; i<b; i++)
#define ROF(i, a, b) for(int i=b-1; i>=a; i--)
#define siz(x) (int) x.size()
#define f first 
#define s second
#define pb push_back
#define trav(x, v) for(auto& x : v)

const int mxN = 1e5+10;
const ll infLL = 1e18+10;

int n, m;
vector<array<int, 3>> adj[mxN];
ll dist[mxN][2];
int vis[mxN];
int lst[mxN];
priority_queue<pair<ll,  pair<int, int> >, vector<pair<ll, pair<int, int>>>, greater<pair<ll, pair<int, int>>>> pq;;

int32_t main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n >> m;
    F0R(i, n) lst[i] = -1e9;
    F0R(i, m){
        int a, b, c, d; cin >> a >> b >> c >> d; a--; b--; 
        adj[a].pb({b, c, d}); adj[b].pb({a, c, d});
    }
    FOR(i, 1, n) dist[i][0] = dist[i][1]  = infLL;
    pq.push({0, {0, -1e9}});
    while(!pq.empty()){
        auto T = pq.top(); pq.pop();
        if(vis[T.s.f]==2||(vis[T.s.f]==1&&lst[T.s.f]==T.s.s)) continue;
        //cout << T.f << ' ' << T.s.f << ' ' << T.s.s << "\n";
        dist[T.s.f][vis[T.s.f]] = T.f;
        vis[T.s.f]++;
        lst[T.s.f] = T.s.s;
        map<int, ll> col;
        trav(v, adj[T.s.f]){
            if(v[0]==-T.s.s) continue;
            if(v[1]!=T.s.s) col[v[1]] += v[2];
        }
        trav(v, adj[T.s.f]){
            if(v[0]==-T.s.s) continue;
            if(v[1]!=T.s.s){
                pq.push({T.f+col[v[1]]-v[2], {v[0], v[1]}});
            }
            pq.push({T.f+v[2], {v[0], -T.s.f}});
        }
    }
    cout << (dist[n-1][0]==infLL?-1:dist[n-1][0]) << "\n";

    return 0;
}

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