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Submission #343215

# Submission time Handle Problem Language Result Execution time Memory
343215 2021-01-03T14:29:25 Z blue Portals (BOI14_portals) C++11
70 / 100
 1000 ms 159872 KB 
#include <iostream>
#include <vector>
#include <set>
using namespace std;

int R;
int C;
vector<int> edge[1002*1002];
vector<int> dist[1002*1002];
vector<int> blocked(1002*1002, 1);

vector<int> go_up(1002*1002, -1);
vector<int> go_down(1002*1002, -1);
vector<int> go_left(1002*1002, -1);
vector<int> go_right(1002*1002, -1);


vector<int> min_dist(1002*1002, 1e9);

int start;
int cake;

int u, v, w;

int pos(int r, int c)
{
    return (C+2)*r + c;
}

int pair_dist(int x, int y)
{
    return abs( (x % (C+2)) - (y % (C+2)) )  +  abs( (x / (C+2)) - (y / (C+2)) );
}







struct distcomp
{
    int i;
};

bool operator < (distcomp A, distcomp B)
{
    if(min_dist[A.i] == min_dist[B.i]) return A.i < B.i;
    return min_dist[A.i] < min_dist[B.i];
}








int main()
{
//Input
    cin >> R >> C;

    char c;

    for(int i = 1; i <= R; i++)
    {
        for(int j = 1; j <= C; j++)
        {
            cin >> c;
            if(c == '#') continue;

            blocked[pos(i, j)] = 0;

            if(c == 'S') start = pos(i, j);
            else if(c == 'C') cake = pos(i, j);
        }
    }





    for(int i = 0; i < 1002*1002; i++)
    {
        go_up[i] = go_left[i] = go_down[i] = go_right[i] = i;
    }






    for(int i = 0; i < 1002*1002; i++)
    {
        if(blocked[i]) continue;
        go_up[i] = go_up[i - (C+2)];
        go_left[i] = go_left[i-1];
    }

    for(int i = 1002*1002 - 1; i >= 0; i--)
    {
        if(blocked[i]) continue;
        go_down[i] = go_down[i + (C+2)];
        go_right[i] = go_right[i+1];
    }






    for(int i = 1; i <= R; i++)
    {
        for(int j = 1; j <= C; j++)
        {
            u = pos(i, j); //try swapping the two blocks of code.
            if(blocked[u]) continue;

            for(int v: {u-1, u+1, u-(C+2), u+(C+2)})
            {
                if(blocked[v]) continue;
                edge[u].push_back(v);
                dist[u].push_back(1);
            }



            w = 1e9;
            for(int q: {go_left[u], go_right[u], go_up[u], go_down[u]})
            {
                w = min(w, pair_dist(u, q) - 1);
            }

            for(int q: {go_left[u] + 1, go_right[u] - 1, go_up[u] + (C+2), go_down[u] - (C+2)} )
            {
                if(pair_dist(u, q) > w+1)
                {
                    edge[u].push_back(q);
                    dist[u].push_back(w+1);
                }
            }

            // cout << "u: " << u << '\n';
            // for(int g = 0; g < edge[u].size(); g++)
            // {
            //     cout << edge[u][g] << ' ' << dist[u][g] << '\n';
            // }
            // cout << "________________________________\n";
        }
    }









    min_dist[start] = 0;
    set<distcomp> tbv;
    for(int i = 1; i <= R; i++)
        for(int j = 1; j <= C; j++)
            if(!blocked[pos(i, j)])
                tbv.insert(distcomp{pos(i, j)});


    while(!tbv.empty())
    {
        u = tbv.begin()->i;
        tbv.erase(tbv.begin());

        for(int i = 0; i < edge[u].size(); i++)
        {
            v = edge[u][i];
            w = dist[u][i];

            if(min_dist[v] > min_dist[u] + w)
            {
                tbv.erase(distcomp{v});
                min_dist[v] = min_dist[u] + w;
                tbv.insert(distcomp{v});
            }
        }
    }


    cout << min_dist[cake] << '\n';
}

Compilation message

portals.cpp: In function 'int main()':
portals.cpp:174:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  174 |         for(int i = 0; i < edge[u].size(); i++)
      |                        ~~^~~~~~~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 49 ms 71020 KB Output is correct
2 Correct 49 ms 71020 KB Output is correct
3 Correct 51 ms 71020 KB Output is correct
4 Correct 48 ms 71020 KB Output is correct
5 Correct 51 ms 71020 KB Output is correct
6 Correct 55 ms 71020 KB Output is correct
7 Correct 48 ms 71020 KB Output is correct
8 Correct 46 ms 71020 KB Output is correct
9 Correct 45 ms 71020 KB Output is correct
10 Correct 46 ms 71020 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 71020 KB Output is correct
2 Correct 45 ms 71020 KB Output is correct
3 Correct 45 ms 71020 KB Output is correct
4 Correct 114 ms 71020 KB Output is correct
5 Correct 45 ms 71020 KB Output is correct
6 Correct 45 ms 71020 KB Output is correct
7 Correct 44 ms 71020 KB Output is correct
8 Correct 48 ms 71020 KB Output is correct
9 Correct 57 ms 71404 KB Output is correct
10 Correct 52 ms 71404 KB Output is correct
11 Correct 57 ms 71276 KB Output is correct
12 Correct 56 ms 71276 KB Output is correct
13 Correct 59 ms 71276 KB Output is correct
14 Correct 47 ms 71180 KB Output is correct
15 Correct 54 ms 71276 KB Output is correct
16 Correct 57 ms 71020 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 48 ms 71020 KB Output is correct
2 Correct 46 ms 71020 KB Output is correct
3 Correct 48 ms 71020 KB Output is correct
4 Correct 46 ms 71020 KB Output is correct
5 Correct 86 ms 73708 KB Output is correct
6 Correct 77 ms 73836 KB Output is correct
7 Correct 82 ms 74220 KB Output is correct
8 Correct 75 ms 74096 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 50 ms 71148 KB Output is correct
2 Correct 50 ms 71020 KB Output is correct
3 Correct 50 ms 71020 KB Output is correct
4 Correct 50 ms 71148 KB Output is correct
5 Correct 51 ms 71020 KB Output is correct
6 Correct 50 ms 71020 KB Output is correct
7 Correct 51 ms 71020 KB Output is correct
8 Correct 49 ms 71020 KB Output is correct
9 Correct 53 ms 71404 KB Output is correct
10 Correct 52 ms 71404 KB Output is correct
11 Correct 52 ms 71276 KB Output is correct
12 Correct 53 ms 71276 KB Output is correct
13 Correct 52 ms 71276 KB Output is correct
14 Correct 77 ms 73728 KB Output is correct
15 Correct 80 ms 73836 KB Output is correct
16 Correct 82 ms 74220 KB Output is correct
17 Correct 81 ms 74220 KB Output is correct
18 Correct 88 ms 75244 KB Output is correct
19 Correct 99 ms 76780 KB Output is correct
20 Correct 103 ms 76780 KB Output is correct
21 Correct 77 ms 73708 KB Output is correct
22 Correct 78 ms 73708 KB Output is correct
23 Correct 80 ms 73964 KB Output is correct
24 Correct 99 ms 76652 KB Output is correct
25 Correct 51 ms 71020 KB Output is correct
26 Correct 52 ms 71276 KB Output is correct
27 Correct 49 ms 71020 KB Output is correct
28 Correct 74 ms 74092 KB Output is correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 49 ms 71020 KB Output is correct
2 Correct 50 ms 71020 KB Output is correct
3 Correct 50 ms 71020 KB Output is correct
4 Correct 51 ms 71148 KB Output is correct
5 Correct 50 ms 71020 KB Output is correct
6 Correct 50 ms 71020 KB Output is correct
7 Correct 50 ms 71020 KB Output is correct
8 Correct 51 ms 71020 KB Output is correct
9 Correct 51 ms 71404 KB Output is correct
10 Correct 52 ms 71404 KB Output is correct
11 Correct 51 ms 71276 KB Output is correct
12 Correct 52 ms 71276 KB Output is correct
13 Correct 51 ms 71276 KB Output is correct
14 Correct 76 ms 73708 KB Output is correct
15 Correct 79 ms 73836 KB Output is correct
16 Correct 82 ms 74220 KB Output is correct
17 Correct 81 ms 74220 KB Output is correct
18 Correct 89 ms 75244 KB Output is correct
19 Correct 102 ms 76908 KB Output is correct
20 Correct 103 ms 76652 KB Output is correct
21 Correct 78 ms 73672 KB Output is correct
22 Correct 84 ms 73708 KB Output is correct
23 Correct 79 ms 73964 KB Output is correct
24 Execution timed out 1093 ms 159872 KB Time limit exceeded
25 Halted 0 ms 0 KB -