제출 #319340

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
319340		jainbot27	Olympic Bus (JOI20_ho_t4)	C++17	100 / 100	920 ms	6020 KiB

ho_t4

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

#define f first
#define s second
#define pb push_back
#define ar array
#define all(x) x.begin(), x.end()
#define siz(x) (int)x.size()

#define FOR(x, y, z) for(int x = (y); x < (z); x++)
#define ROF(x, z, y) for(int x = (y-1); x >= (z); x--)
#define F0R(x, z) FOR(x, 0, z)
#define R0F(x, z) ROF(x, 0, z)
#define trav(x, y) for(auto&x:y)

using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using pii = pair<int, int>;
using vpii = vector<pair<int, int>>;
using pli = pair<ll, int>;
using vpli = vector<pli>;

template<class T> inline bool ckmin(T&a, T b) {return b < a ? a = b, 1 : 0;}
template<class T> inline bool ckmax(T&a, T b) {return b > a ? a = b, 1 : 0;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const char nl = '\n';
const int mxN = 201;
const int mxM = 5e4 + 10;
const int MOD = 1e9 + 7;
const long long infLL = 1e18;

struct edge{
    int v, i; ll c;
    edge(int V, ll C, int I){
        v = V;
        c = C;
        i = I;
    }
};

int n, m;
int u[mxM], v[mxM]; ll c[mxM], d[mxM];
pii par[2][mxN][mxN]; ll dist[2][mxN][mxN];
int used[2][mxM];
vector<edge> adj[2][mxN];

ll ans = 0;

void go(int u, int gl){
    priority_queue<pli, vpli, greater<pli>> pq;
    fill(dist[gl][u], dist[gl][u] + n, infLL);
    dist[gl][u][u]=0;
    par[gl][u][u]={-1, -1};
    pq.push({0, u});
    while(!pq.empty()){
        pii cur = pq.top();
        pq.pop();
        if(cur.f != dist[gl][u][cur.s]){
            continue;
        } 
        trav(nxt, adj[gl][cur.s]){
            if(ckmin(dist[gl][u][nxt.v], cur.f + nxt.c)){
                pq.push({dist[gl][u][nxt.v], nxt.v});
                par[gl][u][nxt.v]= {nxt.i, cur.s};
            }
        }
    } 
}

void findPath(int gl){
    if(dist[0][(gl?n-1:0)][(gl?0:n-1)] == infLL){
        return;
    }
    int u = (gl ? n-1 : 0), v = (gl ? 0 : n - 1);
    while(v != u){
        used[gl][par[0][u][v].f]=1;
        v=par[0][u][v].s; 
    }
}

ll go(int u, int v, int cant){
    vector<ll> d(n, infLL);
    d[u]=0;
    priority_queue<pli, vpli, greater<pli>> pq;
    pq.push({0, u});
    while(!pq.empty()){
        pli cur = pq.top();
        pq.pop();
        if(cur.f != d[cur.s]) continue;
        trav(x, adj[0][cur.s]){
            if(x.i != cant){
                if(ckmin(d[x.v], cur.f + x.c)){
                    pq.push({d[x.v], x.v});
                }
            }
        }
        trav(x, adj[1][cur.s]){
            if(x.i == cant){
                if(ckmin(d[x.v], cur.f + x.c)){
                    pq.push({d[x.v], x.v});
                }
            }
        }
    }
    //F0R(i, n){ cout << d[i] << ' ';
    //}
    //cout << nl;
    return d[v];
}

int32_t main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n >> m;
    F0R(i, m){
        cin >> u[i] >> v[i] >> c[i] >> d[i]; u[i]--; v[i]--;
        adj[0][u[i]].pb({v[i], c[i], i});
        adj[1][v[i]].pb({u[i], c[i], i});
    } 
    F0R(i, n){
        go(i, 0);
        //go(i, 1);
    } 
    findPath(0); findPath(1);
    ans=dist[0][0][n-1]+dist[0][n-1][0];
    ll tmp[2] = {dist[0][0][n-1], dist[0][n-1][0]};
    F0R(i, m){
        ll res = d[i];
        F0R(chk, 2){
            if(used[chk][i]){
                res += go(chk?n-1:0, chk?0:n-1, i);
            }
            else{
                res += min(tmp[chk], dist[0][(chk?n-1:0)][v[i]]+dist[0][u[i]][chk?0:n-1]+c[i]);
            }
        }
        ckmin(ans, res);
    }
    cout << (ans >= infLL ? -1 : ans) << nl;
    return 0;
}

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