#include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
#define int ll
#define f first
#define s second
#define pii pair<int, int>
#define vi vector<int>
#define pb push_back
using namespace std;
const int maxn = 1e3 + 10;
int a[maxn][maxn];
int n, m;
vector<pii> p;
vector<pii> pd;
int cnt = 0;
int used[maxn][maxn];
int dfs(int x, int y) {
p.pb({x, y});
used[x][y] = 1;
if (x == n - 1 && y == m - 1)
return 1;
if (x + 1 < n && !a[x + 1][y] && !used[x + 1][y]) {
if (dfs(x + 1, y))
return 1;
}
if (y + 1 < m && !a[x][y + 1] && !used[x][y + 1]) {
if (dfs(x, y + 1))
return 1;
}
p.pop_back();
return 0;
};
int dfsd(int x, int y) {
cnt++;
used[x][y] = 1;
pd.pb({x, y});
if (x == n - 1 && y == m - 1)
return 1;
if (y + 1 < m && !a[x][y + 1] && !used[x][y + 1]) {
if (dfsd(x, y + 1))
return 1;
}
if (x + 1 < n && !a[x + 1][y] && !used[x + 1][y]) {
if (dfsd(x + 1, y))
return 1;
}
pd.pop_back();
return 0;
};
int dfs2(int i) {
auto [x, y] = p[i];
if (x == n - 1 && y == m - 1)
return 1;
// cout << x << ' ' << y << '\n';
if (x + 1 < n && !a[x + 1][y]) {
if (p[i + 1] == make_pair(x + 1, y))
return 1;
auto [t1, t2] = p[i + 1];
p[i + 1] = {x + 1, y};
if (dfs2(i + 1))
return 1;
p[i + 1] = {t1, t2};
}
if (y + 1 < m && !a[x][y + 1]) {
if (p[i + 1] == make_pair(x, y + 1))
return 1;
auto [t1, t2] = p[i + 1];
p[i + 1] = {x, y + 1};
if (dfs2(i + 1))
return 1;
p[i + 1] = {t1, t2};
}
a[x][y] = 1;
return 0;
}
int dfs2d(int i) {
auto [x, y] = pd[i];
if (x == n - 1 && y == m - 1)
return 1;
// cout << x << ' ' << y << '\n';
a[x][y] = 1;
if (y + 1 < m && !a[x][y + 1]) {
if (pd[i + 1] == make_pair(x, y + 1)) {
a[x][y] = 0;
return 1;
}
auto [t1, t2] = pd[i + 1];
pd[i + 1] = {x, y + 1};
if (dfs2d(i + 1)) {
a[x][y] = 0;
return 1;
}
pd[i + 1] = {t1, t2};
}
if (x + 1 < n && !a[x + 1][y]) {
if (pd[i + 1] == make_pair(x + 1, y)) {
a[x][y] = 0;
return 1;
}
auto [t1, t2] = pd[i + 1];
pd[i + 1] = {x + 1, y};
if (dfs2d(i + 1)) {
a[x][y] = 0;
return 1;
}
pd[i + 1] = {t1, t2};
}
return 0;
}
void solve() {
cin >> n >> m;
for (int i = 0; i < n; ++i)
for (int j = 0; j < m; ++j)
cin >> a[i][j];
int len = n + m - 1;
dfs(0, 0);
memset(used, 0, sizeof(used));
dfsd(0, 0);
int q;
cin >> q;
auto binu = [&] (int x, int y) {
int l = 0, r = len;
while (r - l > 1) {
int mid = (l + r) / 2;
if (make_pair(x, y) >= p[mid])
l = mid;
else
r = mid;
}
return (p[l] == make_pair(x, y) ? l : 1e9);
};
auto bind = [&] (int x, int y) {
int l = 0, r = len;
while (r - l > 1) {
int mid = (l + r) / 2;
auto s = pd[mid];
swap(s.f, s.s);
if (make_pair(y, x) >= s)
l = mid;
else
r = mid;
}
return (p[l] == make_pair(x, y) ? l : 1e9);
};
while (q--) {
int x, y;
cin >> x >> y;
x--;
y--;
int u = binu(x, y);
int d = bind(x, y);
if (u < len && d < len) {
cout << 0 << "\n";
} else {
cout << 1 << '\n';
if (u < len) {
int j = u;
a[x][y] = 1;
j--;
while (j >= 0 && !dfs2(j)) {
j--;
}
} else if (d < len) {
int j = d;
a[x][y] = 1;
j--;
while (j >= 0 && !dfs2d(j)) {
j--;
}
}
}
cout.flush();
}
}
signed main() {
// #ifdef LOCAL
// freopen("input.txt", "r", stdin);
// #endif // LOCAL
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.precision(10);
int t = 1;
// cin >> t;
while (t--)
solve();
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
6 ms |
8684 KB |
Output is correct |
| 2 |
Incorrect |
13 ms |
8812 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
6 ms |
8684 KB |
Output is correct |
| 2 |
Incorrect |
13 ms |
8812 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
