#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 1000
#define M 1000
#define Q 1000000
#define INF 0x3f3f3f3f
int min(int a, int b) { return a < b ? a : b; }
int max(int a, int b) { return a > b ? a : b; }
void append(int **ej, int *eo, int i, int j) {
int o = eo[i]++;
if (o >= 2 && (o & o - 1) == 0)
ej[i] = (int *) realloc(ej[i], o * 2 * sizeof *ej[i]);
ej[i][o] = j;
}
int tt[N * M + 1][2], pp[N * M + 1], sz[N * M + 1];
int dir(int u) {
return tt[pp[u]][0] == u ? 0 : 1;
}
int is_root(int u) {
return pp[u] == 0 || tt[pp[u]][dir(u)] != u;
}
void pul(int u) {
sz[u] = sz[tt[u][0]] + sz[tt[u][1]] + 1;
}
void attach(int u, int v, int d) {
if (u)
tt[u][d] = v, pul(u);
if (v)
pp[v] = u;
}
void rotate(int u) {
int v = pp[u], w = pp[v], du = dir(u), dv = dir(v), top = is_root(v);
attach(v, tt[u][du ^ 1], du);
attach(u, v, du ^ 1);
if (top)
pp[u] = w;
else
attach(w, u, dv);
}
void splay(int u) {
while (!is_root(u)) {
if (!is_root(pp[u]))
rotate(dir(u) == dir(pp[u]) ? pp[u] : u);
rotate(u);
}
}
void expose(int u) {
int v, w;
for (v = u, w = 0; v; w = v, v = pp[v])
splay(v), attach(v, w, 1);
splay(u);
}
void link(int u, int v) {
expose(v), expose(u);
attach(u, v, 1);
}
void cut(int u, int v) {
expose(v), expose(u);
attach(u, 0, 1), pp[v] = 0;
}
int ancestor(int u, int k) {
expose(u);
while (1)
if (k < sz[tt[u][1]])
u = tt[u][1];
else if (k > sz[tt[u][1]])
k -= sz[tt[u][1]] + 1, u = tt[u][0];
else {
splay(u);
return u;
}
}
int main() {
static char cc[N][M + 1];
static int ii1[Q], jj1[Q], kk1[Q], ii2[Q], jj2[Q], kk2[Q], dp[N][M], dq[N][M], *eij[N + M], eo[N + M], *eh[N + M], eo_[N + M];
static char active[N][M], yes[Q];
int n, m, q, h, i, i1, i2, j, j1, j2, ij, k, k1, k2, r, o;
scanf("%d%d%d", &n, &m, &q);
for (i = 0; i < n; i++)
scanf("%s", cc[i]);
for (h = 0; h < q; h++) {
scanf("%d%d%d%d", &ii1[h], &jj1[h], &ii2[h], &jj2[h]), ii1[h]--, jj1[h]--, ii2[h]--, jj2[h]--;
kk1[h] = ii1[h] + jj1[h], kk2[h] = ii2[h] + jj2[h];
}
for (i = 0; i < n; i++)
for (j = 0; j < m; j++)
if (cc[i][j] == '#')
dp[i][j] = INF;
else {
dp[i][j] = i + j;
if (i > 0)
dp[i][j] = min(dp[i][j], dp[i - 1][j]);
if (j > 0)
dp[i][j] = min(dp[i][j], dp[i][j - 1]);
}
for (i = n - 1; i >= 0; i--)
for (j = m - 1; j >= 0; j--)
if (cc[i][j] == '#')
dq[i][j] = -1;
else {
dq[i][j] = i + j;
if (i + 1 < n)
dq[i][j] = max(dq[i][j], dq[i + 1][j]);
if (j + 1 < m)
dq[i][j] = max(dq[i][j], dq[i][j + 1]);
}
for (k = 0; k < n + m; k++)
eij[k] = (int *) malloc(2 * sizeof *eij[k]);
for (i = 0; i < n; i++)
for (j = 0; j < m; j++)
if (cc[i][j] == '.')
append(eij, eo, dq[i][j], i * m + j);
for (k = 0; k < n + m; k++)
eh[k] = (int *) malloc(2 * sizeof *eh[k]);
for (h = 0; h < q; h++) {
i1 = ii1[h], j1 = jj1[h], k1 = kk1[h], i2 = ii2[h], j2 = jj2[h], k2 = kk2[h];
if (k1 > k2 || dq[i1][j1] < k2 || dp[i2][j2] > k1)
yes[h] = 0;
else
yes[h] = 1, append(eh, eo_, kk2[h], h);
}
for (r = 0; r < 2; r++) {
for (i = 0; i < n; i++)
memset(active[i], 0, n * sizeof *active[i]);
memset(pp, 0, n * m * sizeof *pp);
for (i = 1; i <= n * m; i++)
tt[i][0] = tt[i][1] = 0, sz[i] = 1;
for (k = n + m - 1; k >= 0; k--) {
for (o = eo[k]; o--; ) {
ij = eij[k][o], i = ij / m, j = ij % m;
active[i][j] = 1;
if (r == 0) {
if (i + 1 < n && active[i + 1][j])
link((i + 1) * m + j + 1, i * m + j + 1);
else if (j + 1 < m && active[i][j + 1])
link(i * m + (j + 1) + 1, i * m + j + 1);
if (i > 0 && active[i - 1][j]) {
if (j + 1 < m && active[i - 1][j + 1])
cut((i - 1) * m + (j + 1) + 1, (i - 1) * m + j + 1);
link(i * m + j + 1, (i - 1) * m + j + 1);
}
if (j > 0 && active[i][j - 1] && (i + 1 == n || !active[i + 1][j - 1]))
link(i * m + j + 1, i * m + (j - 1) + 1);
} else {
if (j + 1 < m && active[i][j + 1])
link(i * m + (j + 1) + 1, i * m + j + 1);
else if (i + 1 < n && active[i + 1][j])
link((i + 1) * m + j + 1, i * m + j + 1);
if (j > 0 && active[i][j - 1]) {
if (i + 1 < n && active[i + 1][j - 1])
cut((i + 1) * m + (j - 1) + 1, i * m + (j - 1) + 1);
link(i * m + j + 1, i * m + (j - 1) + 1);
}
if (i > 0 && active[i - 1][j] && (j + 1 == m || !active[i - 1][j + 1]))
link(i * m + j + 1, (i - 1) * m + j + 1);
}
}
for (o = eo_[k]; o--; ) {
h = eh[k][o], i1 = ii1[h], j1 = jj1[h], k1 = kk1[h], i2 = ii2[h], j2 = jj2[h], k2 = kk2[h];
ij = ancestor(i1 * m + j1 + 1, k2 - k1) - 1;
if ((r == 0 ? ij < i2 * m + j2 : ij > i2 * m + j2))
yes[h] = 0;
}
}
}
for (h = 0; h < q; h++)
printf(yes[h] ? "YES\n" : "NO\n");
return 0;
}
Compilation message
Main.c: In function 'append':
Main.c:16:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
16 | if (o >= 2 && (o & o - 1) == 0)
| ~~^~~
Main.c: In function 'main':
Main.c:98:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
98 | scanf("%d%d%d", &n, &m, &q);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.c:100:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
100 | scanf("%s", cc[i]);
| ^~~~~~~~~~~~~~~~~~
Main.c:102:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
102 | scanf("%d%d%d%d", &ii1[h], &jj1[h], &ii2[h], &jj2[h]), ii1[h]--, jj1[h]--, ii2[h]--, jj2[h]--;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
235 ms |
41388 KB |
Output is correct |
| 2 |
Correct |
252 ms |
41052 KB |
Output is correct |
| 3 |
Incorrect |
199 ms |
41080 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
235 ms |
41388 KB |
Output is correct |
| 2 |
Correct |
252 ms |
41052 KB |
Output is correct |
| 3 |
Incorrect |
199 ms |
41080 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
