#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<string> s(n + 2, string(m + 2, '#'));
for (int i = 1; i <= n; i++)
{
string t;
cin >> t;
t = "#" + t + "#";
s[i] = t;
}
n += 2, m += 2;
vector<vector<int> > up(n, vector<int>(m));
for (int i = 1; i < n; i++)
{
for (int j = 0; j < m; j++)
{
up[i][j] = up[i - 1][j];
if (s[i - 1][j] == '#')
up[i][j] = i;
}
}
vector<vector<int> > down(n, vector<int>(m));
for (int i = n - 2; i >= 0; i--)
{
for (int j = 0; j < m; j++)
{
down[i][j] = down[i + 1][j];
if (s[i + 1][j] == '#')
down[i][j] = i;
}
}
vector<vector<int> > right(n, vector<int>(m));
vector<vector<int> > left(n, vector<int>(m));
for (int i = 0; i < n; i++)
{
for (int j = 1; j < m; j++)
{
left[i][j] = left[i][j - 1];
if (s[i][j - 1] == '#')
left[i][j] = j;
}
}
for (int i = 0; i < n; i++)
{
for (int j = m - 2; j >= 0; j--)
{
right[i][j] = right[i][j + 1];
if (s[i][j + 1] == '#')
right[i][j] = j;
}
}
vector<int> cx = {0, 0, -1, 1};
vector<int> cy = {1, -1, 0, 0};
int sx, sy, fx, fy;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
if (s[i][j] == 'S') sx = i, sy = j;
if (s[i][j] == 'C') fx = i, fy = j;
}
}
const int INF = 1e9;
vector<vector<int> > dist(n, vector<int>(m, INF));
vector<vector<int> > wall(n, vector<int>(m, INF));
dist[sx][sy] = 0;
vector<pair<int, int> > q = {};
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
if (s[i][j] == '#')
q.push_back({i, j}), wall[i][j] = 0;
}
}
auto ok = [&](int i, int j){
return 0 <= i && i < n && 0 <= j && j < m;
};
for (int i = 0; i < q.size(); i++)
{
int x = q[i].first, y = q[i].second;
for (int k = 0; k < 4; k++)
{
int nx = x + cx[k], ny = y + cy[k];
if (ok(nx, ny) && s[nx][ny] != '#' && wall[nx][ny] > wall[x][y] + 1)
{
wall[nx][ny] = wall[x][y] + 1;
q.push_back({nx, ny});
}
}
}
typedef pair<int, int> pii;
set<pair<int, pii> > S;
S.insert({0, {sx, sy}});
while (S.size())
{
auto it = S.begin();
int x = (*it).second.first;
int y = (*it).second.second;
//cout << x << " " << y << " " << dist[x][y] << endl;
S.erase(S.begin());
for (int k = 0; k < 4; k++)
{
int nx = x + cx[k], ny = y + cy[k];
if (ok(nx, ny) && s[nx][ny] != '#' && dist[nx][ny] > dist[x][y] + 1)
{
S.erase({dist[nx][ny], {nx, ny}});
dist[nx][ny] = dist[x][y] + 1;
S.insert({dist[nx][ny], {nx, ny}});
}
}
{
int nx = up[x][y], ny = y;
if (dist[nx][ny] > dist[x][y] + wall[x][y])
{
S.erase({dist[nx][ny], {nx, ny}});
dist[nx][ny] = dist[x][y] + wall[x][y];
S.insert({dist[nx][ny], {nx, ny}});
}
}
{
int nx = down[x][y], ny = y;
if (dist[nx][ny] > dist[x][y] + wall[x][y])
{
S.erase({dist[nx][ny], {nx, ny}});
dist[nx][ny] = dist[x][y] + wall[x][y];
S.insert({dist[nx][ny], {nx, ny}});
}
}
{
int nx = x, ny = right[x][y];
if (dist[nx][ny] > dist[x][y] + wall[x][y])
{
S.erase({dist[nx][ny], {nx, ny}});
dist[nx][ny] = dist[x][y] + wall[x][y];
S.insert({dist[nx][ny], {nx, ny}});
}
}
{
int nx = x, ny = left[x][y];
if (dist[nx][ny] > dist[x][y] + wall[x][y])
{
S.erase({dist[nx][ny], {nx, ny}});
dist[nx][ny] = dist[x][y] + wall[x][y];
S.insert({dist[nx][ny], {nx, ny}});
}
}
}
cout << dist[fx][fy];
}
Compilation message
portals.cpp: In function 'int main()':
portals.cpp:89:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
89 | for (int i = 0; i < q.size(); i++)
| ~~^~~~~~~~~~
portals.cpp:76:16: warning: 'sy' may be used uninitialized in this function [-Wmaybe-uninitialized]
76 | dist[sx][sy] = 0;
| ^
portals.cpp:76:12: warning: 'sx' may be used uninitialized in this function [-Wmaybe-uninitialized]
76 | dist[sx][sy] = 0;
| ^
portals.cpp:159:24: warning: 'fy' may be used uninitialized in this function [-Wmaybe-uninitialized]
159 | cout << dist[fx][fy];
| ^
portals.cpp:159:20: warning: 'fx' may be used uninitialized in this function [-Wmaybe-uninitialized]
159 | cout << dist[fx][fy];
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
1 ms |
364 KB |
Output is correct |
6 |
Correct |
1 ms |
364 KB |
Output is correct |
7 |
Correct |
1 ms |
364 KB |
Output is correct |
8 |
Correct |
1 ms |
364 KB |
Output is correct |
9 |
Correct |
1 ms |
364 KB |
Output is correct |
10 |
Correct |
1 ms |
492 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
1 ms |
364 KB |
Output is correct |
6 |
Correct |
1 ms |
364 KB |
Output is correct |
7 |
Correct |
1 ms |
364 KB |
Output is correct |
8 |
Correct |
1 ms |
384 KB |
Output is correct |
9 |
Correct |
1 ms |
504 KB |
Output is correct |
10 |
Correct |
1 ms |
492 KB |
Output is correct |
11 |
Correct |
1 ms |
492 KB |
Output is correct |
12 |
Correct |
1 ms |
512 KB |
Output is correct |
13 |
Correct |
1 ms |
492 KB |
Output is correct |
14 |
Correct |
1 ms |
364 KB |
Output is correct |
15 |
Correct |
1 ms |
492 KB |
Output is correct |
16 |
Correct |
1 ms |
364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
9 ms |
2028 KB |
Output is correct |
6 |
Correct |
11 ms |
2028 KB |
Output is correct |
7 |
Correct |
11 ms |
2028 KB |
Output is correct |
8 |
Correct |
5 ms |
2028 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
1 ms |
364 KB |
Output is correct |
6 |
Correct |
1 ms |
364 KB |
Output is correct |
7 |
Correct |
1 ms |
364 KB |
Output is correct |
8 |
Correct |
1 ms |
364 KB |
Output is correct |
9 |
Correct |
2 ms |
492 KB |
Output is correct |
10 |
Correct |
2 ms |
492 KB |
Output is correct |
11 |
Correct |
1 ms |
492 KB |
Output is correct |
12 |
Correct |
1 ms |
492 KB |
Output is correct |
13 |
Correct |
1 ms |
512 KB |
Output is correct |
14 |
Correct |
12 ms |
2028 KB |
Output is correct |
15 |
Correct |
10 ms |
2028 KB |
Output is correct |
16 |
Correct |
11 ms |
2028 KB |
Output is correct |
17 |
Correct |
11 ms |
2028 KB |
Output is correct |
18 |
Correct |
13 ms |
2028 KB |
Output is correct |
19 |
Correct |
13 ms |
2028 KB |
Output is correct |
20 |
Correct |
12 ms |
2028 KB |
Output is correct |
21 |
Correct |
9 ms |
2028 KB |
Output is correct |
22 |
Correct |
10 ms |
2028 KB |
Output is correct |
23 |
Correct |
11 ms |
2028 KB |
Output is correct |
24 |
Correct |
12 ms |
2028 KB |
Output is correct |
25 |
Correct |
1 ms |
364 KB |
Output is correct |
26 |
Correct |
1 ms |
492 KB |
Output is correct |
27 |
Correct |
1 ms |
364 KB |
Output is correct |
28 |
Correct |
6 ms |
2028 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
1 ms |
364 KB |
Output is correct |
6 |
Correct |
1 ms |
364 KB |
Output is correct |
7 |
Correct |
1 ms |
364 KB |
Output is correct |
8 |
Correct |
1 ms |
364 KB |
Output is correct |
9 |
Correct |
1 ms |
492 KB |
Output is correct |
10 |
Correct |
1 ms |
492 KB |
Output is correct |
11 |
Correct |
2 ms |
492 KB |
Output is correct |
12 |
Correct |
1 ms |
492 KB |
Output is correct |
13 |
Correct |
1 ms |
492 KB |
Output is correct |
14 |
Correct |
9 ms |
2028 KB |
Output is correct |
15 |
Correct |
10 ms |
2028 KB |
Output is correct |
16 |
Correct |
11 ms |
2028 KB |
Output is correct |
17 |
Correct |
11 ms |
2028 KB |
Output is correct |
18 |
Correct |
14 ms |
2028 KB |
Output is correct |
19 |
Correct |
12 ms |
2028 KB |
Output is correct |
20 |
Correct |
13 ms |
2156 KB |
Output is correct |
21 |
Correct |
9 ms |
2028 KB |
Output is correct |
22 |
Correct |
10 ms |
2048 KB |
Output is correct |
23 |
Correct |
11 ms |
2028 KB |
Output is correct |
24 |
Correct |
300 ms |
34528 KB |
Output is correct |
25 |
Correct |
481 ms |
35152 KB |
Output is correct |
26 |
Correct |
363 ms |
34528 KB |
Output is correct |
27 |
Correct |
399 ms |
34572 KB |
Output is correct |
28 |
Correct |
215 ms |
34528 KB |
Output is correct |
29 |
Correct |
245 ms |
34656 KB |
Output is correct |
30 |
Correct |
295 ms |
34564 KB |
Output is correct |
31 |
Correct |
11 ms |
2028 KB |
Output is correct |
32 |
Correct |
363 ms |
34528 KB |
Output is correct |
33 |
Correct |
1 ms |
364 KB |
Output is correct |
34 |
Correct |
1 ms |
492 KB |
Output is correct |
35 |
Correct |
268 ms |
34528 KB |
Output is correct |
36 |
Correct |
1 ms |
364 KB |
Output is correct |
37 |
Correct |
6 ms |
2028 KB |
Output is correct |
38 |
Correct |
137 ms |
34528 KB |
Output is correct |
39 |
Correct |
188 ms |
34528 KB |
Output is correct |