# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
115716 | luciocf | Portal (COCI17_portal) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
const int maxn = 510;
const int inf = 1e9+10;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
int n, m;
int ox, oy, dx, dy;
int direction[4][maxn][maxn];
int dist[maxn][maxn];
int dp[maxn][maxn];
bool mark[maxn][maxn];
char tab[maxn][maxn];
int linha[] = {-1, 1, 0, 0};
int coluna[] = {0, 0, -1, 1};
void calcDirection(void)
{
for (int i = 0; i <= n+1; i++)
{
for (int j = 0; j <= m+1; j++)
{
if (tab[i][j] == '#')
direction[0][i][j] = i;
else
direction[0][i][j] = direction[0][i-1][j];
}
for (int j = 0; j <= m+1; j++)
{
if (tab[i][j] == '#')
direction[1][i][j] = j;
else
direction[1][i][j] = direction[1][i][j-1];
}
}
for (int i = n+1; i >= 0; i--)
{
for (int j = 0; j <= m+1; j++)
{
if (tab[i][j] == '#')
direction[2][i][j] = i;
else
direction[2][i][j] = direction[2][i+1][j];
}
for (int j = m+1; j >= 1; j--)
{
if (tab[i][j] == '#')
direction[3][i][j] = j;
else
direction[3][i][j] = direction[3][i][j+1];
}
}
}
void solve(void)
{
for (int i = 0; i <= n+1; i++)
{
for (int j = 0; j <= m+1; j++)
if (tab[i][j] != '#')
dp[i][j] = min({dp[i][j], dp[i][j-1]+1, i-direction[0][i][j]});
for (int j = m+1; j >= 1; j--)
if (tab[i][j] != '#')
dp[i][j] = min({dp[i][j], dp[i][j+1]+1, i-direction[0][i][j]});
}
for (int i = n+1; i >= 1; i--)
{
for (int j = 0; j <= m+1; j++)
if (tab[i][j] != '#')
dp[i][j] = min({dp[i][j], dp[i][j-1]+1, direction[2][i][j]-i});
for (int j = m+1; j >= 1; j--)
if (tab[i][j] != '#')
dp[i][j] = min({dp[i][j], dp[i][j+1]+1, direction[2][i][j]-i});
}
}
void dijkstra(void)
{
for (int i = 0; i <= n+1; i++)
for (int j = 0; j <= m+1; j++)
dist[i][j] = inf;
dist[ox][oy] = 0;
priority_queue<piii, vector<piii>, greater<piii>> fila;
fila.push({0, {ox, oy}});
while (!fila.empty())
{
int x = fila.top().second.first, y = fila.top().second.second;
fila.pop();
if (mark[x][y]) continue;
mark[x][y] = true;
for (int i = 0; i < 4; i++)
{
int a = x+linha[i], b = y+coluna[i];
if (a < 0 || a > n+1 || b < 0 || b > m+1 || tab[a][b] == '#') continue;
if (dist[x][y]+1 < dist[a][b])
{
dist[a][b] = dist[x][y]+1;
fila.push({dist[a][b], {a, b}});
}
}
int delta = dp[x][y];
int a = direction[0][x][y] + 1;
if (dist[x][y]+delta < dist[a][y])
{
dist[a][y] = dist[x][y]+delta;
fila.push({dist[a][y], {a, y}});
}
a = direction[2][x][y] - 1;
if (dist[x][y]+delta < dist[a][y])
{
dist[a][y] = dist[x][y]+delta;
fila.push({dist[a][y], {a, y}});
}
int b = direction[1][x][y] + 1;
if (dist[x][y]+d < dist[x][b])
{
dist[x][b] = dist[x][y]+delta;
fila.push({dist[x][b], {x, b}});
}
b = direction[3][x][y] - 1;
if (dist[x][y]+d < dist[x][b])
{
dist[x][b] = dist[x][y]+delta;
fila.push({dist[x][b], {x, b}});
}
}
}
int main(void)
{
scanf("%d %d", &n, &m);
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
scanf(" %c", &tab[i][j]);
if (tab[i][j] == 'C') ox = i, oy = j;
if (tab[i][j] == 'F') dx = i, dy = j;
}
}
for (int i = 0; i <= n; i++)
tab[i][0] = tab[i][m+1] = '#';
for (int j = 0; j <= m; j++)
tab[0][j] = tab[n+1][j] = '#';
calcDirection();
for (int i = 0; i <= n+1; i++)
for (int j = 0; j <= m+1; j++)
if (tab[i][j] != '#')
dp[i][j] = inf;
solve();
dijkstra();
if (dist[dx][dy] == inf)
printf("nemoguce\n");
else
printf("%d\n", dist[dx][dy]);
}