oj.uz

Submission #905191

# Submission time Handle Problem Language Result Execution time Memory
905191 2024-01-12T17:38:06 Z andrei_iorgulescu Olympic Bus (JOI20_ho_t4) C++14
5 / 100
 1000 ms 3140 KB 
#include <bits/stdc++.h>

using namespace std;

const int inf = 1e9;
const int some_fixed_seed = 100;

struct ura
{
    int u,v,c,d;
};

int n,m;
vector<ura>e;
int d[205][205];
vector<pair<int,int>>g[205];

int getdist(int sursa,int destinatie)
{
    vector<int>dist(n + 1);
    for (int i = 1; i <= n; i++)
        dist[i] = inf;
    priority_queue<pair<int,int>>pq;
    pq.push({0,sursa});
    while (!pq.empty())
    {
        int nod = pq.top().second,cost = -pq.top().first;
        pq.pop();
        if (dist[nod] == inf)
        {
            dist[nod] = cost;
            for (auto vecin : g[nod])
                pq.push({-(cost + vecin.second),vecin.first});
        }
    }
    return dist[destinatie];
}

int tryrev(int idx)
{
    for (int i = 1; i <= n; i++)
        g[i].clear();
    for (int i = 0; i < e.size(); i++)
    {
        if (i == idx)
            g[e[i].v].push_back({e[i].u,e[i].c});
        else
            g[e[i].u].push_back({e[i].v,e[i].c});
    }
    int rt = getdist(1,n) + getdist(n,1);
    if (rt > inf)
        return inf;
    return rt;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            if (i != j)
                d[i][j] = inf;
    for (int i = 1; i <= m; i++)
    {
        ura aux;
        cin >> aux.u >> aux.v >> aux.c >> aux.d;
        e.push_back(aux);
        d[aux.u][aux.v] = min(d[aux.u][aux.v],aux.c);
    }
    shuffle(e.begin(),e.end(),default_random_engine(some_fixed_seed));
    for (int k = 1; k <= n; k++)
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                d[i][j] = min(d[i][j],d[i][k] + d[k][j]);
    int ans = d[1][n] + d[n][1];
    for (int i = 0; i < e.size(); i++)
    {
        auto it = e[i];
        int d1 = min(d[1][n],d[1][it.v] + d[it.u][n] + it.c);
        int d2 = min(d[n][1],d[n][it.v] + d[it.u][1] + it.c);
        int cur = d1 + d2 + it.d;
        if (cur < ans)
            ans = min(ans,it.d + tryrev(i));
    }
    if (ans >= inf)
        cout << -1;
    else
        cout << ans;
    return 0;
}

/**
hai sa zicem ca dau invert la muchia u->v
costul o sa fie >= cost_rev + min(dist(1,n),cost_edge + dist(1,v) + dist(u,n)) + min(dist(n,1),cost_edge + dist(n,v) + dist(u,1))
dau random shuffle la muchii si verific o muchie doar daca are acest cost < ans
teoretic as verifica log muchii, asa o sa verific ceva mai multe dar hopefully tot putine
**/

Compilation message

ho_t4.cpp: In function 'int tryrev(int)':
ho_t4.cpp:43:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<ura>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     for (int i = 0; i < e.size(); i++)
      |                     ~~^~~~~~~~~~
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:79:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<ura>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |     for (int i = 0; i < e.size(); i++)
      |                     ~~^~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 600 KB Output is correct
2 Correct 8 ms 604 KB Output is correct
3 Correct 7 ms 604 KB Output is correct
4 Correct 8 ms 604 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 8 ms 600 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 588 KB Output is correct
9 Correct 2 ms 348 KB Output is correct
10 Correct 14 ms 664 KB Output is correct
11 Correct 33 ms 660 KB Output is correct
12 Correct 9 ms 604 KB Output is correct
13 Correct 38 ms 600 KB Output is correct
14 Correct 8 ms 604 KB Output is correct
15 Correct 8 ms 604 KB Output is correct
16 Correct 7 ms 664 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 1752 KB Output is correct
2 Correct 31 ms 3140 KB Output is correct
3 Correct 20 ms 1756 KB Output is correct
4 Correct 8 ms 600 KB Output is correct
5 Correct 8 ms 604 KB Output is correct
6 Correct 8 ms 604 KB Output is correct
7 Correct 7 ms 600 KB Output is correct
8 Correct 1 ms 344 KB Output is correct
9 Execution timed out 1091 ms 2824 KB Time limit exceeded
10 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 604 KB Output is correct
2 Correct 7 ms 600 KB Output is correct
3 Correct 16 ms 1756 KB Output is correct
4 Correct 8 ms 604 KB Output is correct
5 Correct 19 ms 1660 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Execution timed out 1089 ms 2272 KB Time limit exceeded
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 600 KB Output is correct
2 Correct 8 ms 604 KB Output is correct
3 Correct 7 ms 604 KB Output is correct
4 Correct 8 ms 604 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 8 ms 600 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 588 KB Output is correct
9 Correct 2 ms 348 KB Output is correct
10 Correct 14 ms 664 KB Output is correct
11 Correct 33 ms 660 KB Output is correct
12 Correct 9 ms 604 KB Output is correct
13 Correct 38 ms 600 KB Output is correct
14 Correct 8 ms 604 KB Output is correct
15 Correct 8 ms 604 KB Output is correct
16 Correct 7 ms 664 KB Output is correct
17 Correct 20 ms 1752 KB Output is correct
18 Correct 31 ms 3140 KB Output is correct
19 Correct 20 ms 1756 KB Output is correct
20 Correct 8 ms 600 KB Output is correct
21 Correct 8 ms 604 KB Output is correct
22 Correct 8 ms 604 KB Output is correct
23 Correct 7 ms 600 KB Output is correct
24 Correct 1 ms 344 KB Output is correct
25 Execution timed out 1091 ms 2824 KB Time limit exceeded
26 Halted 0 ms 0 KB -