oj.uz

Submission #922425

# Submission time Handle Problem Language Result Execution time Memory
922425 2024-02-05T13:50:29 Z GrindMachine Olympic Bus (JOI20_ho_t4) C++17
16 / 100
 65 ms 7508 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 200 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
const int M = 5e4 + 5;

vector<array<ll,3>> adj[N];
vector<pll> adj2[N];
vector<bool> bridge(M);
vector<bool> vis(N);
vector<ll> tin(N), low(N);
ll timer = 1;

void dfs1(ll u, ll p){
    vis[u] = 1;
    tin[u] = low[u] = timer++;

    for(auto [v,id] : adj2[u]){
        if(v == p) conts;
        if(vis[v]){
            amin(low[u],tin[v]);
        }
        else{
            dfs1(v,u);
            amin(low[u],low[v]);
            if(low[v] > tin[u]){
                bridge[id] = 1;
            }
        }
    }
}

void dfs2(ll u, ll p, ll ignore){
    vis[u] = 1;
    for(auto [v,id] : adj2[u]){
        if(vis[v]) conts;
        if(id == ignore) conts;
        dfs2(v,u,ignore);
    }
}

vector<ll> topo;

void dfs3(ll u){
    vis[u] = 1;
    for(auto [v,id] : adj2[u]){
        if(vis[v]) conts;
        dfs3(v);
    }

    topo.pb(u);
}

void solve(int test_case)
{
    ll n,m; cin >> n >> m;
    vector<array<ll,4>> edges(m+5);

    rep1(i,m){
        ll u,v,w,d; cin >> u >> v >> w >> d;
        adj[u].pb({v,w,i}), adj[v].pb({u,w,i});
        edges[i] = {u,v,w,d};
    }

    auto dijkstra = [&](ll s, ll flipped){
        vector<ll> dis(n+5,inf2);
        dis[s] = 0;
        rep1(i,n) vis[i] = 0;

        rep1(iter,n){
            pll best = {inf2,inf2};
            rep1(u,n){
                if(vis[u]) conts;
                pll px = {dis[u],u};
                amin(best,px);
            }

            ll u = best.ss;
            vis[u] = 1;

            for(auto [v,w,id] : adj[u]){
                if(id != flipped){
                    if(edges[id][0] == u){
                        amin(dis[v],dis[u]+w);
                    }
                }
                else{
                    if(edges[id][0] == v){
                        amin(dis[v],dis[u]+w);
                    }
                }
            }
        }

        return dis;
    };

    auto dijkstra_rev = [&](ll s){
        vector<ll> dis(n+5,inf2);
        dis[s] = 0;
        rep1(i,n) vis[i] = 0;

        rep1(iter,n){
            pll best = {inf2,inf2};
            rep1(u,n){
                if(vis[u]) conts;
                pll px = {dis[u],u};
                amin(best,px);
            }

            ll u = best.ss;
            vis[u] = 1;

            for(auto [v,w,id] : adj[u]){
                if(edges[id][0] == v){
                    amin(dis[v],dis[u]+w);
                }
            }
        }

        return dis;
    };

    auto dis1 = dijkstra(1,-1);
    auto disn = dijkstra(n,-1);
    auto dis1_rev = dijkstra_rev(1);
    auto disn_rev = dijkstra_rev(n);

    rep1(u,n){
        for(auto [v,w,id] : adj[u]){
            if(edges[id][0] == u){
                if(dis1[u]+w == dis1[v]){
                    adj2[u].pb({v,id});
                }
            }
        }
    }

    auto go = [&](ll s){
        ll t = n^1^s;
        rep1(i,n) vis[i] = 0;
        topo.clear();
        dfs3(s);

        vector<ll> dp1(n+5), dp2(n+5);
        dp1[t] = 1;

        trav(u,topo){
            for(auto [v,id] : adj2[u]){
                dp1[u] += dp1[v];
                dp1[u] %= MOD;
            }
        }

        reverse(all(topo));
        vector<ll> inc[n+5];
        rep1(u,n){
            for(auto [v,id] : adj2[u]){
                inc[v].pb(u);
            }
        }

        dp2[s] = 1;

        trav(u,topo){
            trav(v,inc[u]){
                dp2[u] += dp2[v];
                dp2[u] %= MOD;
            }
        }

        rep1(u,n){
            for(auto [v,id] : adj2[u]){
                ll ways = dp1[u]*dp2[v]%MOD;
                if(ways == dp1[n]){
                    bridge[id] = 1;
                }
            }
        }
    };

    if(dis1[n] != inf2){
        go(1);
    }

    rep1(i,n) adj2[i].clear();

    rep1(u,n){
        for(auto [v,w,id] : adj[u]){
            if(edges[id][0] == u){
                if(disn[u]+w == disn[v]){
                    adj2[u].pb({v,id});
                }
            }
        }
    }

    timer = 1;
    fill(all(vis),0);
    if(disn[1] != inf2){
        go(n);
    }

    assert(count(all(bridge),1) <= 2*n);

    ll ans = inf2;
    amin(ans,dis1[n]+disn[1]);

    rep1(i,m){
        auto [u,v,w,d] = edges[i];
        if(bridge[i]){
            ll cost = d+dijkstra(1,i)[n]+dijkstra(n,i)[1];
            amin(ans,cost);
        }
        else{
            ll sp_1_n = min(dis1[n],dis1[v]+w+disn_rev[u]);
            ll sp_n_1 = min(disn[1],disn[v]+w+dis1_rev[u]);
            ll cost = d+sp_1_n+sp_n_1;
            amin(ans,cost);
            if(cost == 1){
                debug(i);
                debug(sp_1_n);
                debug(sp_n_1);
                debug(disn[1]);
            }
        }
    }

    if(ans == inf2) ans = -1;
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message

ho_t4.cpp: In function 'void solve(int)':
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
   46 | #define debug(x) 42
      |                  ^~
ho_t4.cpp:275:17: note: in expansion of macro 'debug'
  275 |                 debug(i);
      |                 ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
   46 | #define debug(x) 42
      |                  ^~
ho_t4.cpp:276:17: note: in expansion of macro 'debug'
  276 |                 debug(sp_1_n);
      |                 ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
   46 | #define debug(x) 42
      |                  ^~
ho_t4.cpp:277:17: note: in expansion of macro 'debug'
  277 |                 debug(sp_n_1);
      |                 ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
   46 | #define debug(x) 42
      |                  ^~
ho_t4.cpp:278:17: note: in expansion of macro 'debug'
  278 |                 debug(disn[1]);
      |                 ^~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 604 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 10 ms 604 KB Output is correct
4 Correct 16 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 492 KB Output is correct
10 Correct 50 ms 604 KB Output is correct
11 Correct 65 ms 612 KB Output is correct
12 Correct 62 ms 604 KB Output is correct
13 Correct 2 ms 600 KB Output is correct
14 Correct 11 ms 892 KB Output is correct
15 Correct 7 ms 600 KB Output is correct
16 Correct 8 ms 604 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 6660 KB Output is correct
2 Correct 20 ms 6468 KB Output is correct
3 Correct 19 ms 6492 KB Output is correct
4 Correct 2 ms 604 KB Output is correct
5 Correct 2 ms 600 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 20 ms 6744 KB Output is correct
10 Correct 19 ms 6748 KB Output is correct
11 Correct 19 ms 6740 KB Output is correct
12 Correct 20 ms 6484 KB Output is correct
13 Correct 19 ms 6748 KB Output is correct
14 Correct 26 ms 7000 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 600 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 19 ms 6188 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 22 ms 7484 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 21 ms 6728 KB Output is correct
9 Correct 26 ms 6748 KB Output is correct
10 Incorrect 22 ms 7508 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 604 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 10 ms 604 KB Output is correct
4 Correct 16 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 492 KB Output is correct
10 Correct 50 ms 604 KB Output is correct
11 Correct 65 ms 612 KB Output is correct
12 Correct 62 ms 604 KB Output is correct
13 Correct 2 ms 600 KB Output is correct
14 Correct 11 ms 892 KB Output is correct
15 Correct 7 ms 600 KB Output is correct
16 Correct 8 ms 604 KB Output is correct
17 Correct 18 ms 6660 KB Output is correct
18 Correct 20 ms 6468 KB Output is correct
19 Correct 19 ms 6492 KB Output is correct
20 Correct 2 ms 604 KB Output is correct
21 Correct 2 ms 600 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 20 ms 6744 KB Output is correct
26 Correct 19 ms 6748 KB Output is correct
27 Correct 19 ms 6740 KB Output is correct
28 Correct 20 ms 6484 KB Output is correct
29 Correct 19 ms 6748 KB Output is correct
30 Correct 26 ms 7000 KB Output is correct
31 Correct 3 ms 600 KB Output is correct
32 Correct 1 ms 348 KB Output is correct
33 Correct 19 ms 6188 KB Output is correct
34 Correct 1 ms 344 KB Output is correct
35 Correct 22 ms 7484 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 21 ms 6728 KB Output is correct
39 Correct 26 ms 6748 KB Output is correct
40 Incorrect 22 ms 7508 KB Output isn't correct
41 Halted 0 ms 0 KB -