Submission #714168

#	Time	Username	Problem	Language	Result	Execution time	Memory
714168		gaga999	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	325 ms	22480 KiB

commuter_pass

#include <cstdio>
#include <stdio.h>
#include <iostream>
#include <math.h>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stdlib.h>
#include <cstring>
#include <string.h>
#include <string>
#include <sstream>
#include <assert.h>
#include <climits>
#include <sstream>
#include <numeric>
#include <time.h>
#include <limits.h>
#include <list>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <iomanip>
#include <complex>
#include <chrono>
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx,avx2,bmi,bmi2,lzcnt,popcnt")
#define lowbit(x) ((x) & -(x))
#define ml(a, b) ((1ll * (a) * (b)) % M)
#define tml(a, b) (a) = ((1ll * (a) * (b)) % M)
#define ad(a, b) ((0ll + (a) + (b)) % M)
#define tad(a, b) (a) = ((0ll + (a) + (b)) % M)
#define mi(a, b) ((0ll + M + (a) - (b)) % M)
#define tmi(a, b) (a) = ((0ll + M + (a) - (b)) % M)
#define tmin(a, b) (a) = min((a), (b))
#define tmax(a, b) (a) = max((a), (b))
#define iter(a) (a).begin(), (a).end()
#define riter(a) (a).rbegin(), (a).rend()
#define init(a, b) memset((a), (b), sizeof(a))
#define cpy(a, b) memcpy((a), (b), sizeof(a))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define pb push_back
#define mpr make_pair
#define ls(i) ((i) << 1)
#define rs(i) ((i) << 1 | 1)
#define INF 0x3f3f3f3f
#define eps 1e-9
#define F first
#define S second
#define N 100005
#define AC cin.tie(0)->sync_with_stdio(0)
using namespace std;
typedef long long llt;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef pair<llt, llt> pll;
typedef pair<llt, int> pli;
typedef complex<double> cd;
// const int M = 998244353;

// random_device rm;
// mt19937 rg(rm());
// default_random_engine rg(rm());
// uniform_int_distribution<int> rd(INT_MIN, INT_MAX);
// uniform_real_distribution<double> rd(0, M_PI);

void db() { cout << "\n"; }
template <class T, class... U>
void db(T a, U... b) { cout << a << " ", db(b...); }

vector<pii> eg[N];
llt ds[N], dt[N], du[N], dv[N], su[N], sv[N], tu[N], tv[N], an, stv;
bool vd[N];
int n, m, s, t, u, v;

struct P
{
    pli u;
    pll uv;
    bool operator<(const P &rh) const { return u > rh.u; }
};

void dij1(int p, llt *dp)
{
    fill(dp, dp + n + 1, 1ll << 60), init(vd, 0);
    priority_queue<pli, vector<pli>, greater<pli>> pq;
    dp[p] = 0, pq.push(mpr(0, p));
    while (!pq.empty())
    {
        pli tp = pq.top();
        pq.pop();
        if (vd[tp.S])
            continue;
        vd[tp.S] = 1;
        for (pii v : eg[tp.S])
            if (!vd[v.S] && v.F + tp.F < dp[v.S])
                pq.push(mpr(dp[v.S] = v.F + tp.F, v.S));
    }
}

void dij2(int p, llt *dp, llt *nu, llt *nv)
{
    fill(dp, dp + n + 1, 1ll << 60), init(vd, 0);
    fill(nu, nu + n + 1, 1ll << 60), fill(nv, nv + n + 1, 1ll << 60);
    priority_queue<P> pq;
    dp[p] = 0, nu[p] = du[p], nv[p] = dv[p];
    pq.push({mpr(0, p), mpr(nu[p], nv[p])});
    while (!pq.empty())
    {
        P tp = pq.top();
        pq.pop();
        if (tp.u.F == dp[tp.u.S])
            tmin(nu[tp.u.S], tp.uv.F), tmin(nv[tp.u.S], tp.uv.S);
        if (vd[tp.u.S])
            continue;
        vd[tp.u.S] = 1;
        tmin(nu[tp.u.S], du[tp.u.S]), tmin(nv[tp.u.S], dv[tp.u.S]);
        for (pii v : eg[tp.u.S])
            if (!vd[v.S] && v.F + tp.u.F <= dp[v.S])
                pq.push({mpr(dp[v.S] = v.F + tp.u.F, v.S), mpr(nu[tp.u.S], nv[tp.u.S])});
    }
}

signed main()
{
    int x, y, w;
    scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
    for (int i = 0; i < m; i++)
    {
        scanf("%d%d%d", &x, &y, &w);
        eg[x].pb(mpr(w, y));
        eg[y].pb(mpr(w, x));
    }
    dij1(u, du), dij1(v, dv);
    dij2(s, ds, su, sv), dij2(t, dt, tu, tv);
    assert(du[v] == dv[u]), assert(ds[t] == dt[s]);
    an = min(du[v], dv[u]), stv = min(ds[t], dt[s]);
    for (int i = 1; i <= n; i++)
    {
        // db(su[i], sv[i], tu[i], tv[i]);
        if (ds[i] + dt[i] <= stv)
        {
            tmin(an, su[i] + tv[i]);
            tmin(an, sv[i] + tu[i]);
        }
    }
    printf("%lld\n", an);
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:134:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  134 |     scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:137:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |         scanf("%d%d%d", &x, &y, &w);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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