Submission #492038

# Submission time Handle Problem Language Result Execution time Memory
492038 2021-12-05T10:44:40 Z collodel Dreaming (IOI13_dreaming) C++17
0 / 100
66 ms 11300 KB
#include "dreaming.h"
#include <vector>
#include <algorithm>
#include <unordered_map>
#include <queue>

#include <iostream>
#include <vector>
#include <bitset>
// #include <ext/pb_ds/tree_policy.hpp>
// #include <ext/pb_ds/assoc_container.hpp>

using namespace std;

// template<typename T>
// using ordered_set = __gnu_pbds::tree<T, __gnu_pbds::null_type, less<T>, __gnu_pbds::rb_tree_tag, __gnu_pbds::tree_order_statistics_node_update>;
// template<typename T, typename S>
// using ordered_map = __gnu_pbds::tree<T, S, less<T>, __gnu_pbds::rb_tree_tag, __gnu_pbds::tree_order_statistics_node_update>;

template<typename T, typename S>
ostream& operator<< (ostream& out, pair<T, S> p) {
    return out << "(" << p.first << ", " << p.second << ")";
}

// any ct except std::string
template<typename Container,
    typename S = typename enable_if<!is_same<Container, string>::value, typename Container::value_type>::type>
ostream& operator<<(ostream& __out, Container &__ct) {
    __out << "{";
    bool first = true;
    for(auto&& __el : __ct) {
        if(!first) __out << ", ";
        __out << __el;
        first = false;
    }
    return __out << "}";
}
// bitset
template<size_t N>
ostream& operator<<(ostream& __out, bitset<N> &__bs) {
    __out << "{";
    for(size_t i = 0; i < N; ++i) __out << (i != 0 ? ", " : "") /*<< boolalpha*/ << __bs[N - i - 1];
    return __out << "}";
}
template<typename Tail> 
void _dbg(Tail T) {
    cerr << T << '\n';
}
template<typename Head, typename... Tail>
void _dbg(Head H, Tail... T) {
    cerr << H << ", ";
    _dbg(T...);
}

#ifdef DEBUG
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: "; _dbg(__VA_ARGS__);
#else
#define dbg(...) 42
#endif

using vi = vector<int>;
using ii = pair<int, int>;
using vii = vector<ii>;

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {

    vector<vii> AL(N, vii());

    for(int i = 0; i < M; ++i) {
        AL[A[i]].emplace_back(B[i], T[i]);
        AL[B[i]].emplace_back(A[i], T[i]);
    }


    vi visited(N, -1);
    vi sizes;
    unordered_map<int, int> dist;

    // calcola le distanze dei cc
    for(int start = 0; start < N; ++start) {
        // non visitato
        if(visited[start] == -1) {
            // calcola longest path, ricalcolala, prova tutti i nodi in mezzo
            dist.clear();
            visited[start] = true;

            // parti da u
            queue<int> q;
            dist[start] = 0;
            q.emplace(start);

            while(!q.empty()) {
                int u = q.front(); q.pop();

                for(auto &[v, w] : AL[u]) {
                    if(dist.find(v) == dist.end()) {
                        dist[v] = dist[u] + w; // una sola strada possibile
                        visited[v] = true;
                        q.emplace(v);
                    }
                }
            }

            dbg(dist);

            int furthest = max_element(dist.begin(), dist.end(), [](const ii &a, const ii &b){
                if(a.second == b.second) {
                    return a.first < b.first;
                }
                return a.second < b.second;
            })->first; // trova l'elemento piu' distante

            // rigira la bfs
            dist.clear();
            dist[furthest] = 0;
            q.emplace(furthest);

            while(!q.empty()) {
                int u = q.front(); q.pop();

                for(auto &[v, w] : AL[u]) {
                    if(dist.find(v) == dist.end()) {
                        dist[v] = dist[u] + w; // una sola strada possibile
                        q.emplace(v);
                    }
                }
            }

            dbg(dist);

            int end = max_element(dist.begin(), dist.end(), [](const ii &a, const ii &b){
                if(a.second == b.second) {
                    return a.first < b.first;
                }
                return a.second < b.second;
            })->first; // trova l'elemento piu' distante

            dbg(end);

            int from = furthest;
            int to = end;

            // percorri tutti i nodi tra start ed end, trova il migliore
            int best = dist[to];

            while(from != to) {
                // avvicinati ad end

                int next = AL[to][0].first;
                int next_dist = dist[next];

                for(auto &[v, w] : AL[to]) {
                    if(dist[v] < next_dist) {
                        next = v;
                        next_dist = dist[v];
                    }
                }

                to = next;

                best = min(best, max(dist[to], dist[end] - dist[to]));
            }
            dbg(best);

            sizes.push_back(best);
        }
    }
 
    dbg(sizes);

    if(sizes.size() == 1) {
        return 0;
    }
    else {
        sort(sizes.rbegin(), sizes.rend());

        return sizes[0] + L + sizes[1];
    }
}

Compilation message

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:58:18: warning: statement has no effect [-Wunused-value]
   58 | #define dbg(...) 42
      |                  ^~
dreaming.cpp:104:13: note: in expansion of macro 'dbg'
  104 |             dbg(dist);
      |             ^~~
dreaming.cpp:58:18: warning: statement has no effect [-Wunused-value]
   58 | #define dbg(...) 42
      |                  ^~
dreaming.cpp:129:13: note: in expansion of macro 'dbg'
  129 |             dbg(dist);
      |             ^~~
dreaming.cpp:58:18: warning: statement has no effect [-Wunused-value]
   58 | #define dbg(...) 42
      |                  ^~
dreaming.cpp:138:13: note: in expansion of macro 'dbg'
  138 |             dbg(end);
      |             ^~~
dreaming.cpp:58:18: warning: statement has no effect [-Wunused-value]
   58 | #define dbg(...) 42
      |                  ^~
dreaming.cpp:163:13: note: in expansion of macro 'dbg'
  163 |             dbg(best);
      |             ^~~
dreaming.cpp:58:18: warning: statement has no effect [-Wunused-value]
   58 | #define dbg(...) 42
      |                  ^~
dreaming.cpp:169:5: note: in expansion of macro 'dbg'
  169 |     dbg(sizes);
      |     ^~~
# Verdict Execution time Memory Grader output
1 Incorrect 66 ms 11300 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 204 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 66 ms 11300 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 33 ms 5484 KB Output is correct
2 Incorrect 30 ms 5580 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 204 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 66 ms 11300 KB Output isn't correct
2 Halted 0 ms 0 KB -