제출 #1333968

#제출 시각아이디문제언어결과실행 시간메모리
1333968retardeOlympic Bus (JOI20_ho_t4)C++20
37 / 100
1096 ms11128 KiB
#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = (int)4e18;
const bool tc = false;

struct edge {
    int u, v, c, d;
};

int n, m;
const int mxn = 201;
vector<pii> adj[mxn];
vector<edge> e;
map<pair<pii, int>, int> id;

void build_adj() {
    for (int i = 0; i < n; i++) adj[i].clear();
    for (auto &x : e) adj[x.u].pb({x.v, x.c});
}

void rev() {
    for (auto &x : e) swap(x.u, x.v);

    map<pair<pii, int>, int> id2;
    for (auto &[k, val] : id) {
        auto [uv, c] = k;
        auto [u, v] = uv;
        id2[{{v, u}, c}] = val;
    }
    id = move(id2);

    build_adj();
}

void dijk(int s, vi &d, vector<pii> &p) {
    d.assign(n, inf);
    p.assign(n, {-1, -1});

    priority_queue<pii, vector<pii>, greater<pii>> q;
    d[s] = 0;
    q.push({0, s});

    while (!q.empty()) {
        auto [dist, u] = q.top();
        q.pop();

        if (dist != d[u]) continue;

        for (auto &neighbour : adj[u]) {
            int v = neighbour.fi;
            int w = neighbour.se;

            if (dist + w < d[v]) {
                d[v] = dist + w;
                p[v] = {u, w};
                q.push({d[v], v});
            }
        }
    }
}

int solve2() {
    vector<int> df1, dtn, dt1, dfn;
    vector<pii> pf1, ptn, pt1, pfn;

    dijk(0, df1, pf1);
    dijk(n - 1, dfn, pfn);

    rev();
    dijk(n - 1, dtn, ptn);
    dijk(0, dt1, pt1);
    rev();

    int ans = inf;
    if (df1[n - 1] < inf && dfn[0] < inf) ans = df1[n - 1] + dfn[0];

    vi intree(m);
    for (int i = 0; i < n; i++) {
        if (pf1[i].fi != -1) intree[id[{{pf1[i].fi, i}, pf1[i].se}]] = 1;
        if (pfn[i].fi != -1) intree[id[{{pfn[i].fi, i}, pfn[i].se}]] = 1;
        if (pt1[i].fi != -1) intree[id[{{i, pt1[i].fi}, pt1[i].se}]] = 1;
        if (ptn[i].fi != -1) intree[id[{{i, ptn[i].fi}, ptn[i].se}]] = 1;
    }

    for (int i = 0; i < m; i++) {
        if (intree[i]) {
            swap(e[i].u, e[i].v);
            build_adj();

            vi d1, d2;
            vector<pii> p1, p2;
            dijk(0, d1, p1);
            dijk(n - 1, d2, p2);

            if (d1[n - 1] < inf && d2[0] < inf) {
                ans = min(ans, d1[n - 1] + d2[0] + e[i].d);
            }

            swap(e[i].u, e[i].v);
            build_adj();
        } else {
            int a = inf, b = inf;

            if (df1[n - 1] < inf) a = min(a, df1[n - 1]);
            if (df1[e[i].v] < inf && dtn[e[i].u] < inf) {
                a = min(a, df1[e[i].v] + e[i].c + dtn[e[i].u]);
            }

            if (dfn[0] < inf) b = min(b, dfn[0]);
            if (dfn[e[i].v] < inf && dt1[e[i].u] < inf) {
                b = min(b, dfn[e[i].v] + e[i].c + dt1[e[i].u]);
            }

            if (a < inf && b < inf) ans = min(ans, e[i].d + a + b);
        }
    }

    return ans;
}

inline void solve() {
    cin >> n >> m;
    e.clear();
    id.clear();
    for (int i = 0; i < n; i++) adj[i].clear();

    for (int i = 0; i < m; i++) {
        int u, v, c, d;
        cin >> u >> v >> c >> d;
        u--, v--;
        e.pb({u, v, c, d});
        id[mp(mp(u, v), c)] = i;
    }

    build_adj();

    int ans = solve2();
    rev();
    ans = min(ans, solve2());

    cout << (ans >= inf / 2 ? -1 : ans) << '\n';
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);

    int t = 1;
    if (tc) cin >> t;
    while (t--) solve();
}
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