Submission #1004449

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004449		Nailuj_217	Furniture (JOI20_furniture)	C++17	0 / 100	35 ms	2648 KiB

furniture

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

const l LEN = 1005;
l n, m;

array<array<bool, LEN>, LEN> grid;
array<array<bool, LEN>, LEN> possible, visited, updatepossible;

bool dfs(l x, l y) {
    if (visited[x][y]) return possible[x][y];
    visited[x][y] = true;
    if (grid[x][y]) return possible[x][y] = false;
    if (x == n && y == m) return possible[x][y] = true;
    if (x != n)
        if (dfs(x+1, y)) possible[x][y] = true;
    if (y != m) 
        if (dfs(x, y+1)) possible[x][y] = true;

    return possible[x][y];
}

bool dfsback(l x, l y) {
    if (!updatepossible[x][y]) return false;
    if (grid[x][y]) return false;
    if (x != n && updatepossible[x+1][y]) return true;
    if (y != m && updatepossible[x][y+1]) return true;
    updatepossible[x][y] = false;
    bool isval = false;
    if (x != 1 && dfsback(x-1, y)) isval = true;
    if (!isval)
    if (y != 1 && dfsback(x, y-1)) isval = true;
    return isval;
}



int main() {

    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            cin >> grid[i][j];


    dfs(1, 1);

    l q, x, y;
    bool left, top;
    cin >> q;
    while (q--) {
        cin >> x >> y;
        if (!possible[x][y]) {
            grid[x][y] = true;
            cout << 1 << "\n";
            continue;
        }
        updatepossible = possible;
        updatepossible[x][y] = false;
        if (x != 1) dfsback(x-1, y);
        if (y != 1) dfsback(x, y-1);
        if (x != 1) dfsback(x-1, y);
        // if (top || left) {
        //     if (x != 1 && top) top = dfsback(x-1, y);
        //     if (y != 1 && left) left = dfsback(x, y-1);
        // }
        if (updatepossible[1][1]) {
            possible = updatepossible;
            grid[x][y] = true;
            cout << 1 << "\n";
        } else {
            cout << 0 << "\n";
        }




    }

    return 0;
}

Compilation message (stderr)

furniture.cpp: In function 'int main()':
furniture.cpp:53:10: warning: unused variable 'left' [-Wunused-variable]
   53 |     bool left, top;
      |          ^~~~
furniture.cpp:53:16: warning: unused variable 'top' [-Wunused-variable]
   53 |     bool left, top;
      |                ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95