Submission #476693

#	Time	Username	Problem	Language	Result	Execution time	Memory
476693		tranxuanbach	Robot (JOI21_ho_t4)	C++17	24 / 100	804 ms	70904 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define endl '\n'
#define fi first
#define se second
#define For(i, l, r) for (int i = l; i < r; i++)
#define ForE(i, l, r) for (int i = l; i <= r; i++)
#define FordE(i, l, r) for (int i = l; i >= r; i--)
#define Fora(v, a) for (auto v: a)
#define bend(a) a.begin(), a.end()
#define isz(a) ((signed)a.size())

using ll = long long;
using ld = long double;
using pii = pair <int, int>;
using vi = vector <int>;
using vpii = vector <pii>;
using vvi = vector <vi>;

const int N = 1e5 + 5, M = 2e5 + 5;

struct Edge{
    int u, v, c, p;

    Edge(){

    }

    Edge(int u, int v, int c, int p): u(u), v(v), c(c), p(p){

    }
};

int n, m;
Edge edges[2 * M];
vi adj[N];

unordered_map <int, vi> mppc[N];
ll dist[2 * M][3];
priority_queue <tuple <ll, int, int>, vector <tuple <ll, int, int>>, greater <tuple <ll, int, int>>> pq;

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen("KEK.inp", "r", stdin);
    // freopen("KEK.out", "w", stdout);
    cin >> n >> m;
    ForE(i, 1, m){
        int u, v, c, p; cin >> u >> v >> c >> p;
        edges[2 * i - 1] = Edge(u, v, c, p);
        edges[2 * i] = Edge(v, u, c, p);
        adj[u].emplace_back(2 * i - 1);
        adj[v].emplace_back(2 * i);
    }

    ForE(i, 1, 2 * m){
        mppc[edges[i].u][edges[i].c].emplace_back(i);
    }
    memset(dist, 0x3f, sizeof(dist));
    dist[1][2] = 0; pq.emplace(dist[1][2], 1, 2);
    while (!pq.empty()){
        ll d; int u, i; tie(d, u, i) = pq.top(); pq.pop();
        if (i == 2){
            Fora(elem, mppc[u]){
                if (isz(elem.se) == 1){
                    if (dist[elem.se[0]][0] > d){
                        dist[elem.se[0]][0] = d;
                        pq.emplace(dist[elem.se[0]][0], elem.se[0], 0);
                    }
                }
                Fora(ti, elem.se){
                    if (dist[ti][1] > d + edges[ti].p){
                        dist[ti][1] = d + edges[ti].p;
                        pq.emplace(dist[ti][1], ti, 1);
                    }
                }
            }
            continue;
        }
        if (dist[edges[u].v][2] > d){
            dist[edges[u].v][2] = d;
            pq.emplace(dist[edges[u].v][2], edges[u].v, 2);
        }
        if (i == 1 and isz(mppc[edges[u].v][edges[u].c]) == 2){
            Fora(ti, mppc[edges[u].v][edges[u].c]){
                if (ti == (u ^ 1)){
                    continue;
                }
                if (dist[ti][0] > d){
                    dist[ti][0] = d;
                    pq.emplace(dist[ti][0], ti, 0);
                }
            }
        }
    }
    cout << (dist[n][2] == dist[0][0] ? -1 : dist[n][2]) << endl;
}

/*
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INPUT:                                            |
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OUTPUT:                                           |
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*/

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