USACO: The Castle

Problem Link : http://train.usaco.org/usacoprob2?a=qBACVBxoOsW&S=castle


/*
PROG: castle
LANG: C++
*/

#include <bits/stdc++.h>

#define pii             pair <int,int>
#define sc              scanf
#define pf              printf
#define Pi              2*acos(0.0)
#define ms(a,b)         memset(a, b, sizeof(a))
#define pb(a)           push_back(a)
#define MP              make_pair
#define db              double
#define ll              long long
#define EPS             10E-10
#define ff              first
#define ss              second
#define sqr(x)          (x)*(x)
#define D(x)            cout<<#x " = "<<(x)<<endl
#define VI              vector <int>
#define DBG             pf("Hi\n")
#define MOD             100007
#define MAX             10000
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define SZ(a)           (int)a.size()
#define sf(a)           scanf("%d",&a)
#define sfl(a)          scanf("%lld",&a)
#define sff(a,b)        scanf("%d %d",&a,&b)
#define sffl(a,b)       scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)     scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)    scanf("%lld %lld %lld",&a,&b,&c)
#define loop(i,n)       for(int i=0;i<n;i++)
#define REP(i,a,b)      for(int i=a;i<=b;i++)
#define TEST_CASE(t)    for(int z=1;z<=t;z++)
#define PRINT_CASE      printf("Case %d: ",z)
#define all(a)          a.begin(),a.end()
#define intlim          2147483648
#define inf             1000000
#define ull             unsigned long long

using namespace std;


/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

/*-----------------------Bitmask------------------*/
//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
bool check(int N,int pos)
{
    return (bool)(N & (1<<pos));
}
/*------------------------------------------------*/

int graph[52][52];
int dp[2505];
int visited[52][52];

int r,c,s,extend=0;

int dfs(int i, int j, int x)
{
//    if(visited[i][j]) return 0;
    visited[i][j]=x;
    int d=0;
    if(!check(graph[i][j],0) && !visited[i][j-1]) d+=1+dfs(i,j-1,x);
    if(!check(graph[i][j],2) && !visited[i][j+1]) d+=1+dfs(i,j+1,x);
    if(!check(graph[i][j],1) && !visited[i-1][j]) d+=1+dfs(i-1,j,x);
    if(!check(graph[i][j],3) && !visited[i+1][j]) d+=1+dfs(i+1,j,x);
    return d;
}

int n,m;

void func(int i, int j,int x)
{
    int t=visited[i][j];
    int d=0;
    if(check(graph[i][j],0) && t!=visited[i][j-1] && j-1>=1)
    {
        d=dp[t]+dp[visited[i][j-1]];
        if(d>extend)
        {
            extend=d;
            r=i,c=j;
            s=0;
        }
        else if(d==extend)
        {
            if(j<c)
            {
                r=i,c=j;
                s=0;
            }
            else if(j==c)
            {
                if(i>r)
                {
                    r=i,j=c;
                    s=0;
                }
            }
        }
    }

    if(check(graph[i][j],2) && t!=visited[i][j+1] && j+1<=m)
    {
        d=dp[t]+dp[visited[i][j+1]];
        if(d>extend)
        {
            extend=d;
            r=i,c=j;
            s=2;
        }
        else if(d==extend)
        {
            if(j<c)
            {
                r=i,c=j;
                s=2;
            }
            else if(j==c)
            {
                if(i>r)
                {
                    r=i,j=c;
                    s=2;
                }
                else if(i==r)
                {
                    if(s!=1)
                    {
                        r=i,j=c;
                        s=2;
                    }
                }
            }
        }
    }

    // if(check(graph[i][j],2) && !visited[i][j+1]) d+=1+dfs(i,j+1,x);
    //if(check(graph[i][j],1) && !visited[i-1][j]) d+=1+dfs(i-1,j,x);
    if(check(graph[i][j],1) && t!=visited[i-1][j] && i-1>=1)
    {
        d=dp[t]+dp[visited[i-1][j]];
        if(d>extend)
        {
            extend=d;
            r=i,c=j;
            s=1;
        }
        else if(d==extend)
        {
            if(j<c)
            {
                r=i,c=j;
                s=1;
            }
            else if(j==c)
            {
                if(i>r)
                {
                    r=i,j=c;
                    s=1;
                }
                else if(i==r)
                {
                    r=i,j=c;
                    s=1;
                }
            }
        }
    }
    //if(check(graph[i][j],3) && !visited[i+1][j]) d+=1+dfs(i+1,j,x);

    if(check(graph[i][j],3) && t!=visited[i+1][j] && i+1<=n)
    {
        d=dp[t]+dp[visited[i+1][j]];
        if(d>extend)
        {
            extend=d;
            r=i,c=j;
            s=3;
        }
        else if(d==extend)
        {
            if(j<c)
            {
                r=i,c=j;
                s=3;
            }
            else if(j==c)
            {
                if(i>r)
                {
                    r=i,j=c;
                    s=3;
                }
            }
        }
    }
}

int main()
{
    freopen("castle.in","r",stdin);
    freopen("castle.out","w",stdout);
    cin>>n>>m;
    swap(n,m);
    REP(i,1,n) REP(j,1,m) cin>>graph[i][j];

    int k=0;
    int ans=-1;
    REP(i,1,n) REP(j,1,m)
    {
        if(!visited[i][j])
        {
            k++;
            dp[k]=dfs(i,j,k)+1;
            ans=max(ans,dp[k]);
        }
    }

    cout<<k<<endl<<ans<<endl;
    REP(i,1,n) REP(j,1,m)
    {
        func(i,j,visited[i][j]);
//        cout<<i<<" "<<j<<" "<<extend<<" "<<s<<endl;
    }
    cout<<extend<<endl;
    cout<<r<<" "<<c;
    if(s==2)pf(" E\n");
    else
        pf(" N\n");
    return 0;
}

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