#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
const int inf = 1e9;
int n, m;
int sx, sy, ex, ey;
int A[1010][1010];
pii L[1010][1010], R[1010][1010], U[1010][1010], D[1010][1010];
int dx[4] = {0, 0, 1, -1};
int dy[4] = {1, -1, 0, 0};
int dist[1010][1010];
int main() {
scanf("%d %d", &n, &m);
for (int i=1; i<=n; i++) {
for (int j=1; j<=m; j++) {
char c;
scanf(" %c", &c);
if (c == '#') A[i][j] = 0;
else A[i][j] = 1;
}
}
scanf("%d %d", &sx, &sy);
scanf("%d %d", &ex, &ey);
for (int i=1; i<=n; i++) {
int p = 1;
for (int j=2; j<=m; j++) {
if (!A[i][j]) p = j;
else L[i][j] = {i, p+1};
}
p = m;
for (int j=m-1; j>=1; j--) {
if (!A[i][j]) p = j;
else R[i][j] = {i, p-1};
}
}
for (int j=1; j<=m; j++) {
int p = 1;
for (int i=2; i<=n; i++) {
if (!A[i][j]) p = i;
else U[i][j] = {p+1, j};
}
p = n;
for (int i=n-1; i>=1; i--) {
if (!A[i][j]) p = i;
else D[i][j] = {p-1, j};
}
}
for (int i=1; i<=n; i++) for (int j=1; j<=m; j++) dist[i][j] = inf;
priority_queue<tuple<int,int,int>> pq;
pq.push({0, sx, sy});
dist[sx][sy] = 0;
while (!pq.empty()) {
auto [c, x, y] = pq.top();
assert(1 <= x && x <= n && 1 <= y && y <= m);
pq.pop();
if (dist[x][y] < c) continue;
for (int i=0; i<4; i++) {
int nx = x + dx[i];
int ny = y + dy[i];
if (!A[nx][ny]) continue;
if (dist[nx][ny] <= c + 2) continue;
dist[nx][ny] = c + 2;
pq.push({c + 2, nx, ny});
}
for (auto &[nx, ny] : {L[x][y], R[x][y], U[x][y], D[x][y]}) {
if (!A[nx][ny]) continue;
if (dist[nx][ny] <= c + 1) continue;
dist[nx][ny] = c + 1;
pq.push({c + 1, nx, ny});
}
}
if (dist[ex][ey] >= inf) printf("-1\n");
else printf("%d\n", dist[ex][ey]);
}
Compilation message
skating.cpp: In function 'int main()':
skating.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
19 | scanf("%d %d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~~
skating.cpp:23:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
23 | scanf(" %c", &c);
| ~~~~~^~~~~~~~~~~
skating.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
28 | scanf("%d %d", &sx, &sy);
| ~~~~~^~~~~~~~~~~~~~~~~~~
skating.cpp:29:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
29 | scanf("%d %d", &ex, &ey);
| ~~~~~^~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
10584 KB |
Output is correct |
2 |
Correct |
2 ms |
10588 KB |
Output is correct |
3 |
Correct |
1 ms |
10784 KB |
Output is correct |
4 |
Correct |
1 ms |
10584 KB |
Output is correct |
5 |
Correct |
2 ms |
10584 KB |
Output is correct |
6 |
Correct |
2 ms |
10840 KB |
Output is correct |
7 |
Correct |
1 ms |
10588 KB |
Output is correct |
8 |
Correct |
1 ms |
10588 KB |
Output is correct |
9 |
Correct |
2 ms |
10584 KB |
Output is correct |
10 |
Correct |
2 ms |
10588 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
10584 KB |
Output is correct |
2 |
Correct |
2 ms |
10588 KB |
Output is correct |
3 |
Correct |
1 ms |
10784 KB |
Output is correct |
4 |
Correct |
1 ms |
10584 KB |
Output is correct |
5 |
Correct |
2 ms |
10584 KB |
Output is correct |
6 |
Correct |
2 ms |
10840 KB |
Output is correct |
7 |
Correct |
1 ms |
10588 KB |
Output is correct |
8 |
Correct |
1 ms |
10588 KB |
Output is correct |
9 |
Correct |
2 ms |
10584 KB |
Output is correct |
10 |
Correct |
2 ms |
10588 KB |
Output is correct |
11 |
Execution timed out |
3051 ms |
21528 KB |
Time limit exceeded |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
10584 KB |
Output is correct |
2 |
Correct |
2 ms |
10588 KB |
Output is correct |
3 |
Correct |
1 ms |
10784 KB |
Output is correct |
4 |
Correct |
1 ms |
10584 KB |
Output is correct |
5 |
Correct |
2 ms |
10584 KB |
Output is correct |
6 |
Correct |
2 ms |
10840 KB |
Output is correct |
7 |
Correct |
1 ms |
10588 KB |
Output is correct |
8 |
Correct |
1 ms |
10588 KB |
Output is correct |
9 |
Correct |
2 ms |
10584 KB |
Output is correct |
10 |
Correct |
2 ms |
10588 KB |
Output is correct |
11 |
Execution timed out |
3051 ms |
21528 KB |
Time limit exceeded |
12 |
Halted |
0 ms |
0 KB |
- |