Submission #1108161

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108161		whatthemomooofun1729	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	203 ms	22076 KiB

commuter_pass

#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <stack>
#include <map>
#include <queue>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cstring>
#include <cmath>
#include <functional>
#include <cassert>
#include <iomanip>
#include <numeric>
#include <bitset>
#include <sstream>
#include <chrono>
#include <random>

#define ff first
#define ss second
#define PB push_back
#define sz(x) int(x.size())
#define rsz resize
#define fch(xxx, yyy) for (auto xxx : yyy) // abusive notation
#define all(x) (x).begin(),(x).end()
#define eps 1e-9

// more abusive notation (use at your own risk):
// #define int ll

using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;

// debugging
void __print(int x) {std::cerr << x;}
void __print(ll x) {std::cerr << x;} /* remember to uncomment this when not using THE MACRO */
void __print(unsigned x) {std::cerr << x;}
void __print(ull x) {std::cerr << x;}
void __print(float x) {std::cerr << x;}
void __print(double x) {std::cerr << x;}
void __print(ld x) {std::cerr << x;}
void __print(char x) {std::cerr << '\'' << x << '\'';}
void __print(const char *x) {std::cerr << '\"' << x << '\"';}
void __print(const string& x) {std::cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V> void __print(const pair<T, V> &x) {std::cerr << '{'; __print(x.ff); std::cerr << ", "; __print(x.ss); std::cerr << '}';}
template<typename T> void __print(const T& x) {int f = 0; std::cerr << '{'; for (auto &i: x) std::cerr << (f++ ? ", " : ""), __print(i); std::cerr << "}";}
void _print() {std::cerr << "]\n";}
template <typename T, typename... V> void _print(T t, V... v) {__print(t); if (sizeof...(v)) std::cerr << ", "; _print(v...);}
void println() {std::cerr << ">--------------------<" << endl;}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

// templates
template <class T> bool ckmin(T &a, const T &b) {return b<a ? a = b, 1 : 0;}
template <class T> bool ckmax(T &a, const T &b) {return b>a ? a = b, 1 : 0;}
template <class T> using gr = greater<T>;
template <class T> using vc = vector<T>;
template <class T> using p_q = priority_queue<T>;
template <class T> using pqg = priority_queue<T, vc<T>, gr<T>>;
template <class T1, class T2> using pr = pair<T1, T2>;
mt19937_64 rng_ll(chrono::steady_clock::now().time_since_epoch().count());
int rng(int M) {return (int)(rng_ll()%M);} /*returns any random number in [0, M) */

// const variables
constexpr int INF = (int)2e9;
constexpr int MOD = 998244353;
constexpr long double EPS = (ld)1e-10, PI = 3.1415926535;
constexpr ll LL_INF = (ll)3e18;
constexpr int mod = (int)1e9 + 7;
constexpr ll inverse = 500000004LL; // inverse of 2 modulo 1e9 + 7

void setIO(const string& str) {// fast input/output
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (str.empty()) return;
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
}

int N, M, S, T, U, V;
vc<vc<pii>> adj;
vc<pll> dp;
vll du, dv, u, v;

signed main() { // TIME YOURSELF !!!
    setIO("");
    cin >> N >> M >> S >> T >> U >> V;
    adj.rsz(N+1);
    du.rsz(N+1, LL_INF), dv.rsz(N+1, LL_INF), u.rsz(N+1, LL_INF), v.rsz(N+1, LL_INF);
    dp.rsz(N+1, {LL_INF, LL_INF});
    for (int i = 0; i < M; ++i) {
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].PB({b, c});
        adj[b].PB({a, c});
    }
    {
        pqg<pr<ll, int>> pq;
        pq.push({0, U});
        du[U] = 0;
        while (!pq.empty()) {
            int vert = pq.top().ss;
            ll d = pq.top().ff;
            pq.pop();
            if (d != du[vert]) continue;
            fch(to, adj[vert]) {
                int uert = to.ff, w = to.ss;
                if (ckmin(du[uert], du[vert] + w)) {
                    pq.push({du[uert], uert});
                }
            }
        }
        pq.push({0, V});
        dv[V] = 0;
        while (!pq.empty()) {
            int vert = pq.top().ss;
            ll d = pq.top().ff;
            pq.pop();
            if (d != dv[vert]) continue;
            fch(to, adj[vert]) {
                int uert = to.ff, w = to.ss;
                if (ckmin(dv[uert], dv[vert] + w)) {
                    pq.push({dv[uert], uert});
                }
            }
        }
    }
    {
        pqg<pr<pll, int>> pq;
        u[S] = du[S], v[S] = dv[S];
        dp[S] = {0, u[S] + v[S]};
        pq.push({dp[S], S});
        while (!pq.empty()) {
            pll p = pq.top().ff;
            int vert = pq.top().ss;
            pq.pop();
            if (p != dp[vert]) continue;
            fch(to, adj[vert]) {
                int uert = to.ff, w = to.ss;
                pll p_;
                p_.ff = p.ff + w;
                ll udist = min(u[vert], du[uert]), vdist = min(v[vert], dv[uert]);
                p_.ss = udist + vdist;
                if (p_ < dp[uert]) {
                    dp[uert] = p_;
                    u[uert] = udist, v[uert] = vdist;
                    pq.push({dp[uert], uert});
                }
            }
        }
    }
    cout << min(dp[T].ss, dv[U]);
    return 0;
}

// TLE -> TRY NOT USING DEFINE INT LONG LONG
// CE -> CHECK LINE 45
// 5000 * 5000 size matrices are kinda big (potential mle)
// Do something, start simpler

Compilation message (stderr)

commuter_pass.cpp: In function 'void setIO(const string&)':
commuter_pass.cpp:89:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:90:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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