Submission #540865

#	Time	Username	Problem	Language	Result	Execution time	Memory
540865		Olympia	Nautilus (BOI19_nautilus)	C++17	66 / 100	1045 ms	51452 KiB

nautilus

#include <cmath>
#include <iostream>
#include <set>
#include <climits>
#include <cstdio>
#include <algorithm>
#include <cassert>
#include <string>
#include <vector>
#include <iomanip>
#include <unordered_map>
#include <type_traits>
#include <string>
#include <queue>
#define ll long long
#include <map>

using namespace std;
vector<string> vec;
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    set<pair<int,int>> pos;
    int R, C, M;
    cin >> R >> C >> M;
    vec.resize(R);
    for (int i = 0; i < R; i++) {
        cin >> vec[i];
        assert(vec[i].size() == C);
    }
    string s;
    cin >> s;
    set<pair<int,int>> orig;
    for (int i = 0; i < R; i++) {
        for (int j = 0; j < C; j++) {
            if (vec[i][j] == '.') {
                pos.insert({i, j});
            }
        }
    }
    orig = pos;
    map<char,pair<int,int>> myMap;
    myMap['W'] = {0, -1};
    myMap['E'] = {0, 1};
    myMap['S'] = {1, 0};
    myMap['N'] = {-1, 0};
    for (int i = 0; i < s.length(); i++) {
        set<pair<int,int>> valid;
        for (char c: {'W', 'N', 'S', 'E'}) {
            if (s[i] == c || s[i] == '?') {
                set<pair<int,int>> new_pos;
                for (auto& p: pos) {
                    int dx = p.first + myMap[c].first;
                    int dy = p.second + myMap[c].second;
                    new_pos.insert({dx, dy});
                }
                vector<pair<int,int>> res;
                set_intersection(new_pos.begin(), new_pos.end(), orig.begin(), orig.end(), std::back_inserter(res));
                for (auto& p: res) {
                    valid.insert(p);
                }
            }
        }
        pos = valid;
    }
    cout << pos.size() << '\n';
}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from nautilus.cpp:7:
nautilus.cpp: In function 'int main()':
nautilus.cpp:29:30: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |         assert(vec[i].size() == C);
      |                ~~~~~~~~~~~~~~^~~~
nautilus.cpp:47:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |     for (int i = 0; i < s.length(); i++) {
      |                     ~~^~~~~~~~~~~~

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