Submission #1220971

#	Time	Username	Problem	Language	Result	Execution time	Memory
1220971		toast12	Furniture (JOI20_furniture)	C++20	100 / 100	131 ms	6784 KiB

furniture

#include <bits/stdc++.h>
using namespace std;

vector<vector<bool>> vacant;
vector<int> diag;

void block(int i, int j) {
    if (i == 0 || j == 0 || i == vacant.size()-1 || j == vacant[i].size()-1) return;
    diag[i+j-1]--;
    vacant[i][j] = false;
    // if the cell north-east to this one is also blocked, it makes no sense to keep the one above this and the one to the right of this vacant
    if (!vacant[i-1][j+1]) {
        if (vacant[i][j+1]) block(i, j+1);
        if (vacant[i-1][j]) block(i-1, j);
    }
    // similarly, if the cell south-west to this one is also blocked, the one to the left of this one and the one below this one can also be blocked
    if (!vacant[i+1][j-1]) {
        if (vacant[i][j-1]) block(i, j-1);
        if (vacant[i+1][j]) block(i+1, j);
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    int n, m;
    cin >> n >> m;
    vector<vector<int>> grid(n+2, vector<int>(m+2));
    diag.resize(n+m+1);
    vacant.resize(n+2, vector<bool>(m+2));
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> grid[i][j];
            diag[i+j-1]++;
            vacant[i][j] = true;
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (grid[i][j] && vacant[i][j]) block(i, j);
        }
    }
    int q;
    cin >> q;
    while (q--) {
        int r, c;
        cin >> r >> c;
        if (!vacant[r][c]) cout << "1\n";
        else if (diag[r+c-1] == 1) cout << "0\n";
        else {
            cout << "1\n";
            block(r, c);
        }
    }
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95