Submission #1045497

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045497		juicy	T-Covering (eJOI19_covering)	C++17	100 / 100	71 ms	11784 KiB

covering

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

const int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};

int n, m;
vector<vector<int>> a;
vector<vector<bool>> spec, vis;

bool inside(int i, int j) {
    return 0 <= i && i < n && 0 <= j && j < m;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);

    cin >> n >> m;
    a = vector(n, vector<int>(m));
    vis = spec = vector(n, vector<bool>(m));
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            cin >> a[i][j];
        }
    } 
    int k; cin >> k;
    long long res = 0;
    while (k--) {
        int s, t; cin >> s >> t;
        spec[s][t] = 1;
        res += a[s][t];
    }
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            if (!vis[i][j] && spec[i][j]) {
                queue<array<int, 2>> q;
                vector<int> cands;
                q.push({i, j});
                vis[i][j] = 1;
                int cnt = 0;
                while (q.size()) {
                    auto [x, y] = q.front(); q.pop();
                    if (!spec[x][y]) {
                        cands.push_back(a[x][y]);
                    } else {
                        ++cnt;
                    }
                    for (int dr = 0; dr < 4; ++dr) {
                        int u = x + dx[dr], v = y + dy[dr];
                        if (inside(u, v) && !vis[u][v] && (spec[x][y] || spec[u][v])) {
                            vis[u][v] = 1;
                            q.push({u, v});
                        }
                    }
                }
                if (cands.size() < 3 * cnt) {
                    cout << "No";
                    exit(0);
                }
                swap(cands.back(), *min_element(cands.begin(), cands.end()));
                res += accumulate(cands.begin(), cands.begin() + 3 * cnt, 0LL);
            }
        }
    }
    cout << res;
    return 0;
}

Compilation message (stderr)

covering.cpp: In function 'int main()':
covering.cpp:62:34: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   62 |                 if (cands.size() < 3 * cnt) {
      |                     ~~~~~~~~~~~~~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 30 / 30