oj.uz

Submission #922445

# Submission time Handle Problem Language Result Execution time Memory
922445 2024-02-05T14:04:45 Z GrindMachine Olympic Bus (JOI20_ho_t4) C++17
100 / 100
 445 ms 7972 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[v]*dp2[u]%MOD;
                if(ways == dp1[s]){
                    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);
    // debug((ll)count(all(bridge),1));

    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 == 16){
                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:276:17: note: in expansion of macro 'debug'
  276 |                 debug(i);
      |                 ^~~~~
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_1_n);
      |                 ^~~~~
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(sp_n_1);
      |                 ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
   46 | #define debug(x) 42
      |                  ^~
ho_t4.cpp:279:17: note: in expansion of macro 'debug'
  279 |                 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 3 ms 604 KB Output is correct
4 Correct 4 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 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 49 ms 604 KB Output is correct
11 Correct 68 ms 604 KB Output is correct
12 Correct 60 ms 604 KB Output is correct
13 Correct 1 ms 600 KB Output is correct
14 Correct 4 ms 604 KB Output is correct
15 Correct 3 ms 604 KB Output is correct
16 Correct 3 ms 604 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 5464 KB Output is correct
2 Correct 17 ms 5468 KB Output is correct
3 Correct 18 ms 5212 KB Output is correct
4 Correct 1 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 18 ms 5528 KB Output is correct
10 Correct 17 ms 5464 KB Output is correct
11 Correct 17 ms 5464 KB Output is correct
12 Correct 18 ms 5468 KB Output is correct
13 Correct 18 ms 5468 KB Output is correct
14 Correct 18 ms 5976 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 612 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 21 ms 5348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 22 ms 6708 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 18 ms 5800 KB Output is correct
9 Correct 18 ms 5724 KB Output is correct
10 Correct 28 ms 6812 KB Output is correct
11 Correct 21 ms 7712 KB Output is correct
12 Correct 23 ms 7972 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 344 KB Output is correct
17 Correct 1 ms 344 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 21 ms 7928 KB Output is correct
20 Correct 20 ms 7516 KB Output is correct
21 Correct 20 ms 7508 KB Output is correct
22 Correct 20 ms 7508 KB Output is correct

Subtask #4
63.0 / 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 3 ms 604 KB Output is correct
4 Correct 4 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 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 49 ms 604 KB Output is correct
11 Correct 68 ms 604 KB Output is correct
12 Correct 60 ms 604 KB Output is correct
13 Correct 1 ms 600 KB Output is correct
14 Correct 4 ms 604 KB Output is correct
15 Correct 3 ms 604 KB Output is correct
16 Correct 3 ms 604 KB Output is correct
17 Correct 17 ms 5464 KB Output is correct
18 Correct 17 ms 5468 KB Output is correct
19 Correct 18 ms 5212 KB Output is correct
20 Correct 1 ms 604 KB Output is correct
21 Correct 1 ms 604 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 18 ms 5528 KB Output is correct
26 Correct 17 ms 5464 KB Output is correct
27 Correct 17 ms 5464 KB Output is correct
28 Correct 18 ms 5468 KB Output is correct
29 Correct 18 ms 5468 KB Output is correct
30 Correct 18 ms 5976 KB Output is correct
31 Correct 1 ms 612 KB Output is correct
32 Correct 1 ms 344 KB Output is correct
33 Correct 21 ms 5348 KB Output is correct
34 Correct 1 ms 348 KB Output is correct
35 Correct 22 ms 6708 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 18 ms 5800 KB Output is correct
39 Correct 18 ms 5724 KB Output is correct
40 Correct 28 ms 6812 KB Output is correct
41 Correct 21 ms 7712 KB Output is correct
42 Correct 23 ms 7972 KB Output is correct
43 Correct 1 ms 348 KB Output is correct
44 Correct 0 ms 348 KB Output is correct
45 Correct 0 ms 348 KB Output is correct
46 Correct 0 ms 344 KB Output is correct
47 Correct 1 ms 344 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 21 ms 7928 KB Output is correct
50 Correct 20 ms 7516 KB Output is correct
51 Correct 20 ms 7508 KB Output is correct
52 Correct 20 ms 7508 KB Output is correct
53 Correct 29 ms 6232 KB Output is correct
54 Correct 38 ms 6492 KB Output is correct
55 Correct 39 ms 6236 KB Output is correct
56 Correct 3 ms 604 KB Output is correct
57 Correct 2 ms 604 KB Output is correct
58 Correct 277 ms 5212 KB Output is correct
59 Correct 315 ms 5212 KB Output is correct
60 Correct 442 ms 5208 KB Output is correct
61 Correct 273 ms 5208 KB Output is correct
62 Correct 315 ms 5212 KB Output is correct
63 Correct 445 ms 5208 KB Output is correct
64 Correct 207 ms 5208 KB Output is correct
65 Correct 248 ms 5212 KB Output is correct
66 Correct 317 ms 5208 KB Output is correct
67 Correct 12 ms 4812 KB Output is correct
68 Correct 20 ms 6492 KB Output is correct
69 Correct 18 ms 6492 KB Output is correct
70 Correct 36 ms 6480 KB Output is correct
71 Correct 32 ms 6488 KB Output is correct
72 Correct 32 ms 6716 KB Output is correct
73 Correct 36 ms 6792 KB Output is correct
74 Correct 38 ms 6748 KB Output is correct