Submission #303001

#	Time	Username	Problem	Language	Result	Execution time	Memory
303001		ant101	Commuter Pass (JOI18_commuter_pass)	C++17	55 / 100	832 ms	67596 KiB

commuter_pass

#include <iostream>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <stack>
#include <queue>
#include <assert.h>
#include <limits>
#include <cstdio>
#include <complex>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
#define mp make_pair
#define f first
#define s second

typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<pd> vpd;

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353; // = (119<<23)+1
const int MX = 4e5+5;
const ll INF = 1e18;
const ld PI = 4*atan((ld)1);
const int dx[4] = {0,1,0,-1}, dy[4] = {1,0,-1,0};


namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        // cin.exceptions(cin.failbit); // ex. throws exception when you try to read letter into int
        if (sz(s)) {
            setIn(s+".in");
            setOut(s+".out");
        } // for USACO
    }
}

using namespace io;

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);
    
    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) {
        re(first); re(rest...);
    }
    
    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}

namespace output {
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T, size_t SZ> void pr(const array<T,SZ>& x);
    template<class T> void pr(const vector<T>& x);
    template<class T> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);
    
    template<class T> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
        pr(first); pr(rest...);
    }
    
    template<class T1, class T2> void pr(const pair<T1,T2>& x) {
        pr("{",x.f,", ",x.s,"}");
    }
    template<class T> void prContain(const T& x) {
        pr("{");
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
        pr("}");
    }
    template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    template<class T> void pr(const vector<T>& x) { prContain(x); }
    template<class T> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
    
    void ps() { pr("\n"); }
    template<class Arg> void ps(const Arg& first) {
        pr(first); ps(); // no space at end of line
    }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
        pr(first," "); ps(rest...); // print w/ spaces
    }
}

using namespace output;

using namespace input;

ll add(ll a, ll b) {
    a += b;
    if(a >= MOD) {
        a -= MOD;
    }
    return a;
}
ll sub(ll a, ll b) {
    a -= b;
    if(a < 0) {
        a += MOD;
    }
    return a;
}

ll mul(ll a, ll b) {
    return (a * b)%MOD;
}

void add_self(ll& a, ll b) {
    a = add(a, b);
}
void sub_self(ll& a, ll b) {
    a = sub(a, b);
}
void mul_self(ll& a, ll b) {
    a = mul(a, b);
}

ll N, M, S, T, U, V;
vpl adj[MX];
ll usp[MX], vsp[MX];
pair<pl, ll> edgelist[MX];
ll good[MX];
ll sp[MX][2][2];

void dijkstra1(ll s) {
    usp[s] = 0;
    using pii = pair<ll, ll>;
    priority_queue<pl, vector<pl>, greater<pl>> q;
    q.push({0, s});
    while (!q.empty()) {
        ll v = q.top().second;
        ll d_v = q.top().first;
        q.pop();
        if (d_v != usp[v]) {
            continue;
        }
        for (auto edge : adj[v]) {
            ll to = edge.first;
            ll len = edgelist[edge.second].second;
            if (usp[v] + len < usp[to]) {
                usp[to] = usp[v] + len;
                q.push({usp[to], to});
            }
        }
    }
}

void dijkstra2(ll s) {
    vsp[s] = 0;
    priority_queue<pl, vector<pl>, greater<pl>> q;
    q.push({0, s});
    while (!q.empty()) {
        ll v = q.top().second;
        ll d_v = q.top().first;
        q.pop();
        if (d_v != vsp[v]) {
            continue;
        }
        for (auto edge : adj[v]) {
            ll to = edge.first;
            ll len = edgelist[edge.second].second;
            if (vsp[v] + len < vsp[to]) {
                vsp[to] = vsp[v] + len;
                q.push({vsp[to], to});
            }
        }
    }
}

void dijkstra3(ll s) {
    sp[s][0][0] = 0;
    priority_queue<pair<pl, pl>, vector<pair<pl, pl>>, greater<pair<pl, pl>>> q;
    q.push({{0, s}, {0, 0}});
    while (!q.empty()) {
        ll v = q.top().f.s;
        ll d_v = q.top().f.f;
        ll inChain = q.top().s.f;
        ll doneChain = q.top().s.s;
        q.pop();
        if (d_v != sp[v][inChain][doneChain]) {
            continue;
        }
        trav(edge, adj[v]) {
            ll to = edge.f;
            ll len = edgelist[edge.s].s;
            if (inChain) {
                if (good[edge.s]) {
                    if (sp[v][inChain][doneChain] < sp[to][inChain][doneChain]) {
                        sp[to][inChain][doneChain] = sp[v][inChain][doneChain];
                        q.push({{sp[to][inChain][doneChain], to}, {1, 0}});
                    }
                } else {
                    if (sp[v][inChain][doneChain]+len < sp[to][0][1]) {
                        sp[to][0][1] = sp[v][inChain][doneChain]+len;
                        q.push({{sp[to][0][1], to}, {0, 1}});
                    }
                }
            } else if (doneChain) {
                if (sp[v][inChain][doneChain]+len < sp[to][0][1]) {
                    sp[to][0][1] = sp[v][inChain][doneChain]+len;
                    q.push({{sp[to][0][1], to}, {0, 1}});
                }
            } else {
                if (good[edge.s]) {
                    if (sp[v][inChain][doneChain] < sp[to][1][0]) {
                        sp[to][1][0] = sp[v][inChain][doneChain];
                        q.push({{sp[to][1][0], to}, {1, 0}});
                    }
                }
                if (sp[v][inChain][doneChain] + len < sp[to][0][0]) {
                    sp[to][0][0] = sp[v][inChain][doneChain] + len;
                    q.push({{sp[to][0][0], to}, {0, 0}});
                }
            }
        }
    }
}

int main() {
    setIO();
    re(N, M, S, T, U, V);
    F0R (i, MX) {
        usp[i] = 1e13;
        vsp[i] = 1e13;
        sp[i][0][0] = 1e13;
        sp[i][0][1] = 1e13;
        sp[i][1][0] = 1e13;
        sp[i][1][1] = 1e13;
    }
    F0R (i, M) {
        ll a, b, c;
        re(a, b, c);
        adj[a].pb({b, i});
        adj[b].pb({a, i+M});
        edgelist[i] = {{a, b}, c};
        edgelist[i+M] = {{b, a}, c};
    }
    dijkstra1(S);
    dijkstra2(T);
//    FOR (i, 1, N+1) {
//        pr(usp[i], " ");
//
//    }
//    ps();
//    FOR (i, 1, N+1) {
//        pr(vsp[i], " ");
//
//    }
//    ps();
    F0R (i, M*2) {
        if (usp[edgelist[i].f.f] + vsp[edgelist[i].f.s] + edgelist[i].s == usp[T]) {
//            ps(edgelist[i].f.f, edgelist[i].f.s, edgelist[i].s, "is 'good'");
            good[i] = true;
        }
    }
    dijkstra3(U);
    ll ret = min({sp[V][0][0], sp[V][0][1], sp[V][1][0]});
    F0R (i, MX) {
        sp[i][0][0] = 1e13;
        sp[i][0][1] = 1e13;
        sp[i][1][0] = 1e13;
        sp[i][1][1] = 1e13;
    }
    dijkstra3(V);
    ret = min({ret, sp[U][0][0], sp[U][0][1], sp[U][1][0]});
    ps(ret);
//    ps(min({sp[V][0][0], sp[V][0][1], sp[V][1][0]}));
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dijkstra1(ll)':
commuter_pass.cpp:176:11: warning: typedef 'using pii = struct std::pair<long long int, long long int>' locally defined but not used [-Wunused-local-typedefs]
  176 |     using pii = pair<ll, ll>;
      |           ^~~
commuter_pass.cpp: In function 'void io::setIn(std::string)':
commuter_pass.cpp:67:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   67 |     void setIn(string s) { freopen(s.c_str(),"r",stdin); }
      |                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp: In function 'void io::setOut(std::string)':
commuter_pass.cpp:68:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   68 |     void setOut(string s) { freopen(s.c_str(),"w",stdout); }
      |                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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