Submission #439212

#	Time	Username	Problem	Language	Result	Execution time	Memory
439212		elazarkoren	T-Covering (eJOI19_covering)	C++17	0 / 100	4 ms	332 KiB

covering

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#define x first
#define y second
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
#define all(v) v.begin(), v.end()
using namespace std;
typedef long long ll;
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;

int x;

int Solve(vi &curr, vi &special, vvi &board) {
    if (curr.empty()) return 0;
    set<pii> p;
    int min_val = infinity;
    int sum = 0;
    for (int i : curr) {
        int y = special[i];
        p.insert({x, y - 1}), p.insert({x, y + 1});
    }
    curr.clear();
    return 0;
}

int main() {
    int n, m;
    cin >> n >> m;
    vvi board(n, vi(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> board[i][j];
        }
    }
    int k;
    cin >> k;
    vi special(k);
    vb visited(m);
    for (int i = 0; i < k; i++) {
        cin >> x >> special[i];
        visited[special[i]] = true;
    }
    sort(all(special));
    int ans = 0;
    vb put(k);
    while (true) {
        bool is_new = false;
        for (int i = 0; i < k; i++) {
            if (put[i]) continue;
            int y = special[i];
            int sum = board[x][y], min_val = infinity, bad = 4;
            if (x) {
                sum += board[x - 1][y];
                bad--;
                chkmin(min_val, board[x - 1][y]);
            }
            if (x < n - 1) {
                sum += board[x + 1][y];
                bad--;
                chkmin(min_val, board[x + 1][y]);
            }
            if (y && !visited[y - 1]) {
                sum += board[x][y - 1];
                bad--;
                chkmin(min_val, board[x][y - 1]);
            }
            if (y < m - 1 && !visited[y + 1]) {
                sum += board[x][y + 1];
                bad--;
                chkmin(min_val, board[x][y + 1]);
            }
            if (bad == 1) {
                ans += sum;
                visited[y - 1] = true;
                visited[y + 1] = true;
                is_new = true;
                put[i] = true;
            } else if (bad > 1) {
                cout << "No";
                return 0;
            } else if ((!i || special[i] - special[i - 1] > 2) && (i == k - 1 || special[i + 1] - special[i] > 2)) {
                ans += sum - min_val;
                visited[y - 1] = true;
                visited[y + 1] = true;
                is_new = true;
                put[i] = true;
            }
        }
        if (!is_new) break;
    }
    int last = 0;
    for (int i = 0; i < k; i++) {
        if (put[i]) {
            last = i + 1;
            continue;
        }
        if (i < k - 1 && special[i + 1] == special[i] + 2 && !put[i + 1]) {
            last = i + 1;
            continue;
        }
        int sum = 0;
        int min_val = infinity;
        for (int j = last; j <= i; j++) {
            int y = special[j];
            chkmin(min_val, board[x - 1][y]);
            chkmin(min_val, board[x + 1][y]);
            chkmin(min_val, board[x][y - 1]);
            sum += board[x - 1][y] + board[x + 1][y] + board[x][y - 1] + board[x][y];
        }
        chkmin(min_val, board[x][special[i] + 1]);
        sum += board[x][special[i] + 1];
        ans += sum - min_val;
        last = i + 1;
    }
//    vi curr;
//    for (int i = 0; i < n; i++) {
//        int y = special[i];
//        int sum = board[x][y], min_val = infinity, bad = 4;
//        if (x) {
//            sum += board[x - 1][y];
//            bad--;
//            chkmin(min_val, board[x - 1][y]);
//        }
//        if (x < n - 1) {
//            sum += board[x + 1][y];
//            bad--;
//            chkmin(min_val, board[x + 1][y]);
//        }
//        if (y && !visited[y - 1]) {
//            sum += board[x][y - 1];
//            bad--;
//            chkmin(min_val, board[x][y - 1]);
//        }
//        if (y < m - 1 && !visited[y + 1]) {
//            sum += board[x][y + 1];
//            bad--;
//            chkmin(min_val, board[x][y + 1]);
//        }
//        if (bad > 1) {
//            cout << "No";
//            return 0;
//        } else if (bad == 1) {
//            Solve(curr, special, board);
//            ans += sum;
//        } else {
//            curr.push_back(i);
//            if (i < n - 1 && special[i + 1] - special[i] > 2) {
//                Solve(curr, special, board);
//            }
//        }
//    }
    cout << ans;
}

Compilation message (stderr)

covering.cpp: In function 'int Solve(vi&, vi&, vvi&)':
covering.cpp:26:9: warning: unused variable 'min_val' [-Wunused-variable]
   26 |     int min_val = infinity;
      |         ^~~~~~~
covering.cpp:27:9: warning: unused variable 'sum' [-Wunused-variable]
   27 |     int sum = 0;
      |         ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 30