#include "bits/stdc++.h"
using namespace std;
#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }
using ll=long long;
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>;
long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (1006)
ll n, m, ways[2][5][MAXN][MAXN], q, vis[MAXN][MAXN], cnt;
bool A[MAXN][MAXN];
ll dx[2][2]={{0,1}, {0,-1}}, dy[2][2]={{1,0}, {-1,0}}, mod[]={ll(1e9+7),ll(1e9+9),0,0,0};
void bfs(ll f,ll s,ll co,ll dir) {
++ cnt;
queue<pi> q;
q.emplace(f,s), vis[f][s]=cnt;
FOR(j,0,4) ways[co][j][f][s] = 1;
while(q.size()){
ll x=q.front().f, y=q.front().s;
q.pop();
FOR(i,0,1) {
ll nx=x+dx[dir][i], ny=y+dy[dir][i];
if(nx < 1 || ny < 1 || nx > n || ny > m || A[nx][ny]) continue;
FOR(j,0,4) { ways[co][j][nx][ny] += ways[co][j][x][y]; if(ways[co][j][nx][ny] >= mod[j]) ways[co][j][nx][ny] -= mod[j]; }
if(vis[nx][ny]==cnt) continue;
vis[nx][ny]=cnt;
q.emplace(nx,ny);
}
}
}
ll fix[5];
void opp(ll f,ll s,ll co,ll dir) {
++ cnt;
queue<pi> q;
q.emplace(f,s), vis[f][s]=cnt;
FOR(j,0,4) fix[j] = ways[co][j][f][s], ways[co][j][f][s] = 0;
while(q.size()){
ll x=q.front().f, y=q.front().s;
q.pop();
FOR(i,0,1) {
ll nx=x+dx[dir][i], ny=y+dy[dir][i];
if(nx < 1 || ny < 1 || nx > n || ny > m || A[nx][ny]) continue;
FOR(j,0,4) { ways[co][j][nx][ny] -= fix[j]; if(ways[co][j][nx][ny] < 0) ways[co][j][nx][ny] += mod[j]; }
if(vis[nx][ny]==cnt) continue;
vis[nx][ny]=cnt;
q.emplace(nx,ny);
}
}
}
int main() {
FAST
cin>>n>>m;
FOR(i,2,4) mod[i] = rand(1e5, 1e9 + 69);
FOR(i,1,n)FOR(j,1,m)cin>>A[i][j];
bfs(1, 1, 0, 0), bfs(n, m, 1, 1); FOR(j,0,4) assert(ways[0][j][n][m] == ways[1][j][1][1]);
cin>>q;
while(q--) {
ll x, y;
cin>>x>>y;
bool can = 0;
FOR(j,0,4) {
if(ways[0][j][x][y] * ways[1][j][x][y] % mod[j] != ways[0][j][n][m]) can = 1;
}
if(can==0) {
cout<<0<<'\n';
continue;
}
cout<<1<<'\n';
A[x][y] = 1;
opp(x, y, 0, 0), opp(x, y, 1, 1);
}
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
62 ms |
4204 KB |
Output is correct |
| 2 |
Incorrect |
19 ms |
5356 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
62 ms |
4204 KB |
Output is correct |
| 2 |
Incorrect |
19 ms |
5356 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
