Submission #63726

#	Time	Username	Problem	Language	Result	Execution time	Memory
63726		Bodo171	Tracks in the Snow (BOI13_tracks)	C++14	84.69 / 100	2081 ms	119436 KiB

tracks

#include <iostream>
#include <fstream>
#include <queue>
using namespace std;
const int nmax=4005;
int d[nmax][nmax];
//pair<int,int> q[2][nmax*nmax];
string s[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)
{

    queue< pair<int,int> > q[2];
    q[0].push({L,C});
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
           d[i][j]=n*m+1;
    d[L][C]=0;
    for(i=0;i<=n*m;i++)
    {
        if(q[use].empty())
            return;
        mx=max(mx,i);
        while(!q[use].empty())
        {
             li=q[use].front().first;ci=q[use].front().second;q[use].pop();
             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)].push({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;getline(cin,s[0]);
    for(i=1;i<=n;i++)
    {
        getline(cin,s[i]);
    }
    dij(1,1);
    cout<<mx+1;
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void dij(int, int)':
tracks.cpp:31:14: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
              if(!E[li][ci])
              ^~
tracks.cpp:45:15: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
               E[li][ci]=1;
               ^

• Subtask 1: 30 / 30
• Subtask 2: 54.6875 / 70