Submission #599794

#	Time	Username	Problem	Language	Result	Execution time	Memory
599794		ljuba	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	457 ms	23740 KiB

commuter_pass

#include <bits/stdc++.h>
#include <queue>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
 
typedef vector<int> vi;
typedef vector<ll> vll;
 
typedef vector<vi> vvi;
typedef vector<vll> vvll;
 
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
typedef vector<pii> vpii;
typedef vector<pll> vpll;
 
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;
 
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()
#define fi first
#define se second
 
template<class T> bool ckmin(T &a, const T &b) {return a > b ? a = b, 1 : 0;}
template<class T> bool ckmax(T &a, const T &b) {return a < b ? a = b, 1 : 0;}
 
namespace debug {
    void __print(int x) {cerr << x;}
    void __print(long long x) {cerr << x;}
    void __print(double x) {cerr << x;}
    void __print(long double x) {cerr << x;}
    void __print(char x) {cerr << '\'' << x << '\'';}
    void __print(const string &x) {cerr << '\"' << x << '\"';}
    void __print(const char *x) {cerr << '\"' << x << '\"';}
    void __print(bool x) {cerr << (x ? "true" : "false");}
 
    template<typename T, typename V>
    void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
    template<typename T>
    void __print(const T &x) {int f = 0; cerr << '{'; for(auto z : x) cerr << (f++ ? "," : ""), __print(z); cerr << "}";}
    void _print() {cerr << "]\n";}
    template <typename T, typename... V>
    void _print(T t, V... v) {__print(t); if(sizeof...(v)) cerr << ", "; _print(v...);}
 
#ifdef ljuba
#define dbg(x...) cerr << "\e[91m" << "LINE(" << __LINE__ << ") -> " << "[" << #x << "] = ["; _print(x)
#else
#define dbg(x...)
#endif
}
 
using namespace debug;
 
const char nl = '\n';
 
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

const int mxN = 3e5 + 12;

vpii adj[mxN];

const ll INF = 1e18 + 12;

vll dijkstra(int n, int s) {
    vll dist(n, INF);

    priority_queue<pll, vpll, greater<>> pq;
    dist[s] = 0;
    pq.push({dist[s], s});

    while(!pq.empty()) {
        auto tren = pq.top();
        pq.pop();

        if(dist[tren.se] != tren.fi) continue;

        for(auto e : adj[tren.se]) {
            if(ckmin(dist[e.fi], dist[tren.se] + e.se)) {
                pq.push({dist[e.fi], e.fi});
            }
        }
    }

    return dist;
}

vll calc(int n, int s, const vll &distU) {
    vll dp(n, INF);

    priority_queue<pll, vpll, greater<>> pq;
    vll dist(n, INF);
    dist[s] = 0;
    pq.push({0, s});

    while(!pq.empty()) {
        auto tren = pq.top();
        pq.pop();

        if(dist[tren.se] != tren.fi) continue;

        ckmin(dp[tren.se], distU[tren.se]);

        for(auto e : adj[tren.se]) {
            if(ckmin(dist[e.fi], dist[tren.se] + e.se)) {
                pq.push({dist[e.fi], e.fi});
            }

            if(dist[e.fi] == dist[tren.se] + e.se) {
                ckmin(dp[e.fi], dp[tren.se]);
            }
        }
    }

    return dp;
}

void solve() {
    int n, m;
    cin >> n >> m;
    int s, t, u, v;
    cin >> s >> t >> u >> v;
    --s, --t, --u, --v;

    for(int i = 0; i < m; ++i) {
        int a, b, w;
        cin >> a >> b >> w;
        --a, --b;
        adj[a].pb({b, w});
        adj[b].pb({a, w});
    }

    auto distU = dijkstra(n, u);
    auto distV = dijkstra(n, v);
    auto distS = dijkstra(n, s);
    auto distT = dijkstra(n, t);

    auto prvi1 = calc(n, s, distU);
    auto prvi2 = calc(n, s, distV);

    auto drugi1 = calc(n, t, distU);
    auto drugi2 = calc(n, t, distV);

    ll ans = distU[v];

    for(int i = 0; i < n; ++i) {
        for(auto e : adj[i]) {
            if(distS[i] + e.se + distT[e.fi] != distS[t]) continue;

            ckmin(ans, prvi1[i] + drugi2[e.fi]);
            ckmin(ans, prvi2[i] + drugi1[e.fi]);
        }
    }

    cout << ans << nl;
}
 
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    int testCases = 1;
    //cin >> testCases;
    while(testCases--)
        solve();
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45