제출 #1270794

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1270794		icebear	Commuter Pass (JOI18_commuter_pass)	C++20	31 / 100	294 ms	16220 KiB

commuter_pass

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

typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;

template<class T>
    bool minimize(T &a, const T &b) {
        if (a > b) return a = b, true;
        return false;
    }

template<class T>
    bool maximize(T &a, const T &b) {
        if (a < b) return a = b, true;
        return false;
    }

#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define FORR(i,a,b) for(int i=(a); i>=(b); --i)
#define REP(i, n) for(int i=0; i<(n); ++i)
#define RED(i, n) for(int i=(n)-1; i>=0; --i)
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define task "icebear"

const int MOD = 1e9 + 7;
const int inf = 1e9 + 27092008;
const ll INF = 1e18 + 27092008;
const int N = 2e5 + 5;
int n, m, S, T, U, V;
vector<ii> G[N];
ll dist[4][N], f[2][N];

void dijkstra(ll dist[], int src) {
    FOR(i, 1, n) dist[i] = INF;
    dist[src] = 0;
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> Q;
    Q.push(mp(0, src));

    while(!Q.empty()) {
        ll du; int u;
        tie(du, u) = Q.top(); Q.pop();
        if (du != dist[u]) continue;
        for(ii x : G[u]) {
            int v, w; tie(v, w) = x;
            if (minimize(dist[v], dist[u] + w))
                Q.push(mp(dist[v], v));
        }
    }
}

ll dp(int src) {
    FOR(i, 1, n) {
        dist[2][i] = f[0][i] = f[1][i] = INF;
    }
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> Q;
    Q.push(mp(0, src));
    dist[2][src] = 0;

    f[0][src] = dist[0][src];
    f[1][src] = dist[1][src];

    while(!Q.empty()) {
        ll du; int u;
        tie(du, u) = Q.top(); Q.pop();
        if (du != dist[2][u]) continue;
        for(ii x : G[u]) {
            int v, w; tie(v, w) = x;
            if (minimize(dist[2][v], dist[2][u] + w)) {
                f[0][v] = min(f[0][u], dist[0][v]);
                f[1][v] = min(f[1][u], dist[1][v]);
                Q.push(mp(dist[2][v], v));
            } else if (dist[2][v] == dist[2][u] + w && f[0][v] + f[1][v] > f[0][u] + f[1][u]) {
                f[0][v] = f[0][u];
                f[1][v] = f[1][u];
            }
        }
    }

    int dest = (src == S ? T : S);
    return f[0][dest] + f[1][dest];
}

void init(void) {
    cin >> n >> m >> S >> T >> U >> V;
    FOR(i, 1, m) {
        int u, v, w;
        cin >> u >> v >> w;
        G[u].pb(mp(v, w));
        G[v].pb(mp(u, w));
    }
}

void process(void) {
    dijkstra(dist[0], U);
    dijkstra(dist[1], V);
    cout << min({dist[0][V], dp(S), dp(T)});
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int tc = 1;
//    cin >> tc;
    while(tc--) {
        init();
        process();
    }
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:112:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:113:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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