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Copy pathbfs.cpp
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130 lines (120 loc) · 2.26 KB
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#include<stdio.h>
#include<stack>
#include<queue>
using namespace std;
int bfs(char m[22][22], int i,int j);
struct node
{
int r,c;
};
typedef struct node Node;
Node newnode(int row,int col)
{
Node n;
n.r=row;
n.c=col;
return n;
}
int M,N;
int main()
{
int i,count,t;
scanf("%d",&t);
while(t--)
{
char m[22][22];
int done[22][22]={0},flag=0;
scanf("%d %d",&M,&N);
for(i=0;i<M;i++)
scanf("%s",m[i]);
count=0;
for(i=0;i<N;i++)
{
if(m[0][i]=='.'&& !done[0][i])
{
if(bfs(m,0,i)==2)
count++;
else {
flag=-1;
break;}
done[0][i]=1;
}
if(m[M-1][i]=='.'&&!done[M-1][i])
{
if(bfs(m,M-1,i)==2)
count++;
else {
flag=-1;
break;}
done[M-1][i]=1;
}
}
for(i=0;i<M;i++)
{
if(m[i][0]=='.'&&!done[i][0])
{
if(bfs(m,i,0)==2)
count++;
else {
flag=-1;
break;}
done[i][0]=1;
}
if(m[i][N-1]=='.'&&!done[i][N-1])
{
if(bfs(m,i,N-1)==2)
count++;
else {
flag=-1;
break;}
done[i][N-1]=1;
}
}
if(count!=2 || flag==-1)
printf("invalid\n");
else
printf("valid\n");
}
return 0;
}
int bfs(char m[22][22], int i,int j)
{
bool visited[22][22];
for(int l=0;l<22;l++)
for(int n=0;n<22;n++) /*Not accepted without this loop*/
visited[l][n]=false;
int ans=0;
queue<Node> Q;
Q.push(newnode(i,j));
visited[i][j]=true;
while(!(Q.empty()))
{
Node *cur=&(Q.front());
Q.pop();
if(cur->r==0||cur->r==M-1||cur->c==0||cur->c==N-1)
{
ans++;
}
if(!visited[cur->r][cur->c-1]&&m[cur->r][cur->c-1]=='.' && cur->c-1>=0)
{
visited[cur->r][cur->c-1]=true;
Q.push(newnode(cur->r,cur->c-1));
}
if(!visited[cur->r][cur->c+1]&&m[cur->r][cur->c+1]=='.'&&cur->c+1<N)
{
visited[cur->r][cur->c+1]=true;
Q.push(newnode(cur->r,cur->c+1));
}
if(!visited[cur->r-1][cur->c]&&m[cur->r-1][cur->c]=='.'&&cur->r-1>=0)
{
visited[cur->r-1][cur->c]=true;
Q.push(newnode(cur->r-1,cur->c));
}
if(!visited[cur->r+1][cur->c]&&m[cur->r+1][cur->c]=='.'&&cur->r+1<M)
{
visited[cur->r+1][cur->c]=true;
Q.push(newnode(cur->r+1,cur->c));
}
}
return ans;
}