제출 #453557

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
453557		Karliver	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	818 ms	31508 KiB

commuter_pass

    
#include <bits/stdc++.h>

#define FIXED_FLOAT(x)  std::fixed <<std::setprecision(20) << (x)
#define all(v) (v).begin(), (v).end()
using namespace  std;
#define forn(i,n) for (int i = 0; i < (n); ++i)
#define rforn(i, n) for(int i = (n) - 1;i >= 0;--i)
using ll = long long;
int mod = (ll)1e9 + 7;
#define PI acos(-1)
typedef pair<ll, ll> pairs;

const ll INF = 2e18;
const int N = 2e5 + 100;
const double eps = 1e-7;

template <class T> using V = vector<T>;  
template <class T> using VV = V<V<T>>;  

template <typename XPAX>
void ckma(XPAX &x, XPAX y) {
    x = (x < y ? y : x);
}
template <typename XPAX>
void ckmi(XPAX &x, XPAX y) {
    x = (x > y ? y : x);
}


vector<pair<ll, ll>> graph[100001];
ll du[100001], dv[100001], ds[100001], dp[2][100001], ans;
bool visited[100001];

void dijkstra1(ll start, ll arr[]) {
    fill(visited, visited + 100001, false);

    priority_queue<pair<ll, ll>> pq;
    pq.push({0, start});
    while (!pq.empty()) {
        ll c, node;
        tie(c, node) = pq.top();
        pq.pop();

        if (!visited[node]) {
            arr[node] = -c;
            visited[node] = true;
            for (auto& i : graph[node]) pq.push({c - i.second, i.first});
        }
    }
}

void dijkstra2(ll start, ll end) {
    fill(dp[0], dp[0] + 100001, LLONG_MAX / 2);
    fill(dp[1], dp[1] + 100001, LLONG_MAX / 2);
    fill(visited, visited + 100001, false);

    priority_queue<pair<ll, pair<ll, ll>>> pq;
    pq.push({0, {start, 0}});
    dp[0][0] = dp[1][0] = LLONG_MAX/ 2;
    while (!pq.empty()) {
        ll c, node, par;
        pair<ll, ll> p;
        tie(c, p) = pq.top();
        tie(node, par) = p;
        pq.pop();

        if (!visited[node]) {
            visited[node] = true;
            ds[node] = -c;
            dp[0][node] = min(du[node], dp[0][par]);
            dp[1][node] = min(dv[node], dp[1][par]);
            for (auto i : graph[node]) pq.push({c - i.second, {i.first, node}});
        } else if (-c == ds[node]) {
            if (min(du[node], dp[0][par]) + min(dv[node], dp[1][par]) <= dp[0][node] + dp[1][node]) {
                dp[0][node] = min(du[node], dp[0][par]);
                dp[1][node] = min(dv[node], dp[1][par]);
            }
        }
    }

    ans = min(ans, dp[0][end] + dp[1][end]);
}


void solve() {

    ll n, m, s, t, u, v;
    cin >> n >> m >> s >> t >> u >> v;
    for (int i = 0; i < m; i++) {
        ll a, b, c;
        cin >> a >> b >> c;
        graph[a].push_back({b, c});
        graph[b].push_back({a, c});
    }

    dijkstra1(u, du);
    dijkstra1(v, dv);

    ans = du[v];

    dijkstra2(s, t);
    dijkstra2(t, s);

    cout << ans << '\n';

}
void test_case() {
    int t;
    cin >> t;
    forn(p, t) {

        //cout << "Case #" << p + 1 << ": ";
        solve();
    }
}
int main() {

    ios::sync_with_stdio(false);
    cin.tie(0);

    solve();

}

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