Submission #748391

#	Time	Username	Problem	Language	Result	Execution time	Memory
748391		vjudge1	Nautilus (BOI19_nautilus)	C++17	0 / 100	1 ms	340 KiB

nautilus

#include <iostream>
#include <bitset>
using namespace std;

const int MAXN = 1005;
const int MAXM = 1005;
const int MAXLEN = 1005;
const int MAXDIRS = 4;

const int DR[MAXDIRS] = {-1, 0, 1, 0};
const int DC[MAXDIRS] = {0, 1, 0, -1};

int N, M;
bitset<MAXN*MAXM> can_submarine_be_here, possible_locations;

int main() {
    cin >> N >> M;
    for (int i = 0; i < N; ++i) {
        string line;
        cin >> line;
        for (int j = 0; j < M; ++j) {
            if (line[j] == '.') {
                can_submarine_be_here.set(i*M+j);
                possible_locations.set(i*M+j);
            }
        }
    }

    string signals;
    cin >> signals;
    for (int i = 0; i < signals.size(); ++i) {
        char d = signals[i];
        if (d == 'N') d = 0;
        else if (d == 'E') d = 1;
        else if (d == 'S') d = 2;
        else if (d == 'W') d = 3;
        else continue; 
        bitset<MAXN*MAXM> new_possible_locations;
        for (int j = possible_locations._Find_first(); j != possible_locations.size(); j = possible_locations._Find_next(j)) {
            int r = j / M;
            int c = j % M;
            int nr = r + DR[d];
            int nc = c + DC[d];
            if (nr >= 0 && nr < N && nc >= 0 && nc < M && can_submarine_be_here[nr*M+nc]) {
                new_possible_locations.set(nr*M+nc);
            }
        }
        possible_locations = new_possible_locations;
    }

    cout << possible_locations.count()-2;

    return 0;
}

Compilation message (stderr)

nautilus.cpp: In function 'int main()':
nautilus.cpp:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for (int i = 0; i < signals.size(); ++i) {
      |                     ~~^~~~~~~~~~~~~~~~
nautilus.cpp:42:29: warning: array subscript has type 'char' [-Wchar-subscripts]
   42 |             int nr = r + DR[d];
      |                             ^
nautilus.cpp:43:29: warning: array subscript has type 'char' [-Wchar-subscripts]
   43 |             int nc = c + DC[d];
      |                             ^

• Subtask 1: 0 / 29
• Subtask 2: 0 / 37
• Subtask 3: 0 / 34