#include <iostream>
#include <fstream>
#include <cstdio>
using namespace std;
const int nmax=4005;
int d[nmax][nmax];
pair<int,int> q[2][nmax*nmax];
char s[nmax][nmax];
int p[2],u[2];
bool E[nmax][nmax];
int use,mx,i,j,dd,n,m,li,ci,lf,cf,di;
int d1[]={-1,0,1,0};
int d2[]={0,-1,0,1};
void dij(int L,int C)
{
p[0]=p[1]=1;
u[0]=u[1]=0;
q[0][++u[0]]={L,C};use=0;
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
d[i][j]=n*m+1,E[i][j]=0;
d[L][C]=0;
for(i=0;i<=n*m;i++)
{
if(p[use]>u[use])
return;
mx=max(mx,i);
for(p[use]=1;p[use]<=u[use];p[use]++)
{
li=q[use][p[use]].first;ci=q[use][p[use]].second;
if(!E[li][ci])
for(di=0;di<4;di++)
{
lf=li+d1[di];cf=ci+d2[di];
if(lf>=1&&cf>=1&&lf<=n&&cf<=m&&(s[lf][cf-1]=='R'||s[lf][cf-1]=='F'))
{
dd=d[li][ci]+(s[li][ci-1]!=s[lf][cf-1]);
if(dd<d[lf][cf])
{
d[lf][cf]=dd;
q[(dd&1)][++u[(dd&1)]]={lf,cf};
}
}
}
E[li][ci]=1;
}
p[use]=1;u[use]=0;
use=1-use;
}
}
int main()
{
//freopen("data.in","r",stdin);
cin>>n>>m;gets(s[0]);
for(i=1;i<=n;i++)
{
gets(s[i]);
}
dij(1,1);
cout<<mx+1;
return 0;
}
Compilation message
tracks.cpp: In function 'int main()':
tracks.cpp:54:15: error: 'gets' was not declared in this scope
cin>>n>>m;gets(s[0]);
^~~~
tracks.cpp:54:15: note: suggested alternative: 'fgets'
cin>>n>>m;gets(s[0]);
^~~~
fgets
