Submission #642244

#	Time	Username	Problem	Language	Result	Execution time	Memory
642244		Ez0zIOVgTsSgT	Robot (JOI21_ho_t4)	C++14	100 / 100	735 ms	84556 KiB

Main

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

void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << h; if(sizeof...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL

#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 each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
#define fi first
#define se second

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;

void setIO(string NAME = "") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(NAME)) {
        freopen((NAME + ".inp").c_str(),"r",stdin);
        freopen((NAME + ".out").c_str(),"w",stdout);
    }
}

tcT> bool ckmin(T&a, const T&b) {
    return b < a ? a=b,1 : 0; }
tcT> bool ckmax(T&a, const T&b) {
    return b > a ? a=b,1 : 0; }

const int MOD = 1e9 + 7;

const ll INF = 1e18;
const int MX = 1e5+5;

struct Edge {
    int to, c;
    ll p;
};

struct Dat {
    ll curdist;
    int u, c;
    bool operator<(const Dat&rhs) const {
        return curdist > rhs.curdist;
    }
};

map<int,V<Edge>> adj[MX];
ll dist[MX];
map<int,ll> dist2[MX], psum[MX];
int N, M;

void solve() {
    cin >> N >> M;
    F0R(i, M) {
        int u, v, c;
        ll p;
        cin >> u >> v >> c >> p;
        adj[u][c].pb({v, c, p});
        adj[v][c].pb({u, c, p});
        psum[u][c] += p;
        psum[v][c] += p;
    }
    memset(dist, 0x3f, sizeof dist);
    dist[1] = 0;
    priority_queue<Dat> pq;
    pq.push({0, 1, 0});
    while(!pq.empty()) {
        ll du = pq.top().curdist;
        int u = pq.top().u, c = pq.top().c;
        pq.pop();
        if(c) {
            if(dist2[u][c] != du) continue;
            each(ed, adj[u][c]) {
                int v = ed.to, col = ed.c;
                ll dv = du + psum[u][col] - ed.p;
                // not flip color c
                if(ckmin(dist[v], dv)) {
                    pq.push({dist[v], v, 0});
                }
            }
        }
        else {
            if(dist[u] != du) continue;
            each(edmp, adj[u]) {
                each(ed, edmp.se) {
                    //CASE 1 : not change this color
                    int v = ed.to;
                    ll dv = du + psum[u][ed.c] - ed.p;
                    if(ckmin(dist[v], dv)) {
                        pq.push({dist[v], v, 0});
                    }
                    //CASE 2 != 1
                    dv = du + ed.p;
                    if(ckmin(dist[v], dv)) {
                        pq.push({dist[v], v, 0});
                    }
                    //CASE 3
                    dv = du;
                    if(dist2[v].find(ed.c) == dist2[v].end() || dv < dist2[v][ed.c]) {
                        dist2[v][ed.c] = dv;
                        pq.push({dv, v, ed.c});
                    }
                }
            }
        }
    }
    ll ans = dist[N];
    if(ans >= INF) ans = -1;
    cout << ans << nl;
}

int main() {
    setIO();

    int t=1;
    //cin>>t;
    while(t-->0) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:39:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         freopen((NAME + ".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:40:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         freopen((NAME + ".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42