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Submission #439342

# Submission time Handle Problem Language Result Execution time Memory
439342 2021-06-29T16:32:47 Z elazarkoren T-Covering (eJOI19_covering) C++17
100 / 100
 607 ms 34724 KB 
#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
typedef vector<bool> vb;
typedef vector<vb> vvb;

const int infinity = 1e9;

vvi board, ind;
vii special;

int dir_x[] = {-1, 1, 0, 0, -1, -1, 1, 1};
int dir_y[] = {0, 0, -1, 1, 1, -1, 1, -1};

set<pii> q;

int ans = 0;
int Dfs(vvi &graph, int node, vb &visited) {
    int x = special[node].x, y = special[node].y;
    q.insert({x - 1, y}), q.insert({x + 1, y}), q.insert({x, y - 1}), q.insert({x, y + 1});
    ans += board[x][y];
    visited[node] = true;
    int sz = 1;
    for (int neighbor : graph[node]) {
        if (!visited[neighbor]) sz += Dfs(graph, neighbor, visited);
    }
    return sz;
}

int main() {
    int n, m;
    cin >> n >> m;
    board.resize(n, vi(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> board[i][j];
        }
    }
    ind.resize(n, vi(m));
    vvb block(n, vb(m));
    int k;
    cin >> k;
    special.resize(k);
    for (int i = 0; i < k; i++) {
        cin >> special[i].x >> special[i].y;
        ind[special[i].x][special[i].y] = i + 1;
        block[special[i].x][special[i].y] = true;
    }
    vb finished(k);
    while (true) {
        bool is_new = false;
        for (int i = 0; i < k; i++) {
            if (finished[i]) continue;
            int x = special[i].x, y = special[i].y;
            int neighbor1 = 4, sum = board[x][y];
            for (int j = 0; j < 4; j++) {
                x += dir_x[j], y += dir_y[j];
                if (0 <= x && x < n && 0 <= y && y < m && !block[x][y]) {
                    neighbor1--;
                    sum += board[x][y];
                }
                x -= dir_x[j], y -= dir_y[j];
            }
            int neighbor2 = 0;
            for (int j = 4; j < 8; j++) {
                x += dir_x[j], y += dir_y[j];
                if (0 <= x && x < n && 0 <= y && y < m && ind[x][y]) {
                    neighbor2++;
                }
                x -= dir_x[j], y -= dir_y[j];
            }
            if (neighbor1 > 1 || neighbor2 > 1) {
                cout << "No";
                return 0;
            }
            if (neighbor1 == 1) {
                ans += sum;
                finished[i] = true;
                is_new = true;
                for (int j = 0; j < 4; j++) {
                    x += dir_x[j], y += dir_y[j];
                    if (0 <= x && x < n && 0 <= y && y < m) block[x][y] = true;
                    x -= dir_x[j], y -= dir_y[j];
                }
                continue;
            }
            if (neighbor2) {
                block[x][y - 1] = true;
                block[x][y + 1] = true;
                ans += board[x][y - 1] + board[x][y + 1] + board[x][y];
                if (ind[x + 1][y + 1] || ind[x + 1][y - 1]) {
                    block[x - 1][y] = true;
                    ans += board[x - 1][y];
                } else {
                    block[x + 1][y] = true;
                    ans += board[x + 1][y];
                }
                finished[i] = true;
                is_new = true;
            }
        }
        if (!is_new) {
            break;
        }
    }
    vvi graph(k);
    for (int i = 0; i < k; i++) {
        if (finished[i]) continue;
        int x = special[i].x, y = special[i].y;
        if (x > 1 && ind[x - 2][y]) {
            graph[i].push_back(ind[x - 2][y] - 1);
        }
        if (y > 1 && ind[x][y - 2]) {
            graph[i].push_back(ind[x][y - 2] - 1);
        }
        if (x < n - 2 && ind[x + 2][y]) {
            graph[i].push_back(ind[x + 2][y] - 1);
        }
        if (y < m - 2 && ind[x][y + 2]) {
            graph[i].push_back(ind[x][y + 2] - 1);
        }
    }
    vb visited(k);
    for (int i = 0; i < k; i++) {
        if (finished[i] || visited[i]) continue;
        q.clear();
        int sz = Dfs(graph, i, visited);
        if (sz * 3 > q.size()) {
            cout << "No";
            return 0;
        }
        int min_val = infinity;
        for (pii p : q) {
            ans += board[p.x][p.y];
            chkmin(min_val, board[p.x][p.y]);
        }
        if (sz * 3 < q.size()) {
            ans -= min_val;
        }
    }
    cout << ans;
}

Compilation message

covering.cpp: In function 'int main()':
covering.cpp:139:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |         if (sz * 3 > q.size()) {
      |             ~~~~~~~^~~~~~~~~~
covering.cpp:148:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  148 |         if (sz * 3 < q.size()) {
      |             ~~~~~~~^~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 8 ms 460 KB Output is correct
3 Correct 27 ms 1052 KB Output is correct
4 Correct 91 ms 2764 KB Output is correct
5 Correct 250 ms 8388 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 332 KB Output is correct
2 Correct 8 ms 460 KB Output is correct
3 Correct 25 ms 1068 KB Output is correct
4 Correct 85 ms 2768 KB Output is correct
5 Correct 252 ms 8320 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 8 ms 460 KB Output is correct
3 Correct 27 ms 1052 KB Output is correct
4 Correct 75 ms 2760 KB Output is correct
5 Correct 247 ms 8388 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 2 ms 204 KB Output is correct
3 Correct 14 ms 804 KB Output is correct
4 Correct 10 ms 588 KB Output is correct
5 Correct 32 ms 1468 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct

Subtask #6
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 8 ms 460 KB Output is correct
3 Correct 27 ms 1052 KB Output is correct
4 Correct 91 ms 2764 KB Output is correct
5 Correct 250 ms 8388 KB Output is correct
6 Correct 4 ms 332 KB Output is correct
7 Correct 8 ms 460 KB Output is correct
8 Correct 25 ms 1068 KB Output is correct
9 Correct 85 ms 2768 KB Output is correct
10 Correct 252 ms 8320 KB Output is correct
11 Correct 3 ms 332 KB Output is correct
12 Correct 8 ms 460 KB Output is correct
13 Correct 27 ms 1052 KB Output is correct
14 Correct 75 ms 2760 KB Output is correct
15 Correct 247 ms 8388 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 2 ms 204 KB Output is correct
18 Correct 14 ms 804 KB Output is correct
19 Correct 10 ms 588 KB Output is correct
20 Correct 32 ms 1468 KB Output is correct
21 Correct 3 ms 332 KB Output is correct
22 Correct 8 ms 652 KB Output is correct
23 Correct 26 ms 1440 KB Output is correct
24 Correct 91 ms 3516 KB Output is correct
25 Correct 252 ms 9216 KB Output is correct

Subtask #7
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 8 ms 460 KB Output is correct
3 Correct 27 ms 1052 KB Output is correct
4 Correct 91 ms 2764 KB Output is correct
5 Correct 250 ms 8388 KB Output is correct
6 Correct 4 ms 332 KB Output is correct
7 Correct 8 ms 460 KB Output is correct
8 Correct 25 ms 1068 KB Output is correct
9 Correct 85 ms 2768 KB Output is correct
10 Correct 252 ms 8320 KB Output is correct
11 Correct 3 ms 332 KB Output is correct
12 Correct 8 ms 460 KB Output is correct
13 Correct 27 ms 1052 KB Output is correct
14 Correct 75 ms 2760 KB Output is correct
15 Correct 247 ms 8388 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 2 ms 204 KB Output is correct
18 Correct 14 ms 804 KB Output is correct
19 Correct 10 ms 588 KB Output is correct
20 Correct 32 ms 1468 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 204 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 3 ms 332 KB Output is correct
27 Correct 8 ms 652 KB Output is correct
28 Correct 26 ms 1440 KB Output is correct
29 Correct 91 ms 3516 KB Output is correct
30 Correct 252 ms 9216 KB Output is correct
31 Correct 607 ms 34724 KB Output is correct
32 Correct 248 ms 13780 KB Output is correct
33 Correct 282 ms 17612 KB Output is correct
34 Correct 256 ms 13388 KB Output is correct
35 Correct 355 ms 26988 KB Output is correct