D. Arthur and Walls
time limit per test
memory limit per test
input
output
Finally it is a day when Arthur has enough money for buying an apartment. He found a great option close to the center of the city with a nice price.
n × m consisting of squares of size 1 × 1. Each of those squares contains either a wall (such square is denoted by a symbol "*" on the plan) or a free space (such square is denoted on the plan by a symbol ".").
Room in an apartment is a maximal connected area consisting of free squares. Squares are considered adjacent if they share a common side.
The old Arthur dream is to live in an apartment where all rooms are rectangles. He asks you to calculate minimum number of walls you need to remove in order to achieve this goal. After removing a wall from a square it becomes a free square. While removing the walls it is possible that some rooms unite into a single one.
Input
n, m (1 ≤ n, m ≤ 2000) denoting the size of the Arthur apartments.
n lines each contain m
*" then it contains a wall.
." then it this cell is free from walls and also this cell is contained in some of the rooms.
Output
n rows each consisting of m
If there are several possible answers, output any of them.
Sample test(s)
input
5 5 .*.*. ***** .*.*. ***** .*.*.
output
.*.*. ***** .*.*. ***** .*.*.
input
6 7 ***.*.* ..*.*.* *.*.*.* *.*.*.* ..*...* *******
output
***...* ..*...* ..*...* ..*...* ..*...* *******
input
4 5 ..... ..... ..*** ..*..
output
#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<queue>
using namespace std;
struct node
{
int x;
int y;
//int cnt;
};
int n,m;
char map[2015][2015];
queue<node>q;
void BFS()
{
struct node t,f;
while(!q.empty())
{
t = q.front();
q.pop();
int i = t.x;
int j = t.y;
int x1,x2,x3,y1,y2,y3;
struct node tt;
for(int k=0; k<4; k++)
{
int cnt = 0;
int ans = 0;
if(k == 0)
{
x1 = i - 1;
y1 = j;
x2 = i - 1;
y2 = j - 1;
x3 = i;
y3 = j - 1;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
else if(k == 1)
{
x1 = i;
y1 = j + 1;
x2 = i - 1;
y2 = j;
x3 = i - 1;
y3 = j + 1;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
else if(k == 2)
{
x1 = i;
y1 = j - 1;
x2 = i + 1;
y2 = j - 1;
x3 = i + 1;
y3 = j;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
else if(k == 3)
{
x1 = i + 1;
y1 = j + 1;
x2 = i + 1;
y2 = j;
x3 = i;
y3 = j + 1;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
}
}
for(int i=0; i<n; i++)
{
printf("%s\n",map[i]);
}
}
int main()
{
while(scanf("%d%d",&n,&m)!=EOF)
{
while(!q.empty())
{
q.pop();
}
for(int i=0; i<n; i++)
{
scanf("%s",map[i]);
}
for(int i=0; i<n; i++)
{
for(int j=0; j<m; j++)
{
int x1,x2,x3,y1,y2,y3;
struct node tt;
for(int k=0; k<4; k++)
{
int cnt = 0;
int ans = 0;
if(k == 0)
{
x1 = i - 1;
y1 = j;
x2 = i - 1;
y2 = j - 1;
x3 = i;
y3 = j - 1;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
else if(k == 1)
{
x1 = i;
y1 = j + 1;
x2 = i - 1;
y2 = j;
x3 = i - 1;
y3 = j + 1;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
else if(k == 2)
{
x1 = i;
y1 = j - 1;
x2 = i + 1;
y2 = j - 1;
x3 = i + 1;
y3 = j;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
else if(k == 3)
{
x1 = i + 1;
y1 = j + 1;
x2 = i + 1;
y2 = j;
x3 = i;
y3 = j + 1;
if(map[i][j] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = i;
tt.y = j;
}
if(map[x1][y1] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x1;
tt.y = y1;
}
if(map[x2][y2] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x2;
tt.y = y2;
}
if(map[x3][y3] == '.')
{
cnt++;
}
else
{
ans++;
tt.x = x3;
tt.y = y3;
}
if(x1<0 || x2<0 || x3 < 0 || x1>=n ||x2>=n || x3>=n || y1<0 || y2<0 || y3 < 0 || y1>=m ||y2>=m || y3>=m || cnt!=3 || ans!=1)
{
continue;
}
map[tt.x][tt.y] = '.';
q.push(tt);
}
}
}
}
BFS();
}
return 0;
}
