Category Graph

UVa – 871 – Counting Cells in a Blob

Arunima Mandal Leave a comment 
#include <bits/stdc++.h>

#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define sz(x)           x.size()
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector<int>
#define vll             vector<long long>
#define pii             pair<int,int>
#define pis             pair<int,string>
#define psi             pair<string,int>
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i<n;i++)
#define loop1(i,n)      for(int i=1;i<=n;i++)
#define stlloop(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
#define case(z)         cout<<"Case "<<z<<": "
#define PI              3.14159265358979323846264338328
#define valid(tx,ty)    tx>=0 && tx<l && ty>=0 && ty<l
#define MAX             2000

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
/*------------------------------------------------*/

int l;
bool vis[30][30];

int dfs(int sx, int sy)
{
    vis[sx][sy]=1;
    int r=0;
    loop0(i,8)
    {
        int tx=sx+fx[i];
        int ty=sy+fy[i];
        if(valid(tx,ty) && vis[tx][ty]==0) r+=1+dfs(tx,ty);
    }
    return r;
}

int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);

    int t;
    bool tst=0;
    cin>>t;
    loop1(z,t)
    {
        if(tst) cout<<endl;
        tst=1;
        ms(vis,0);
        string s;
        cin>>s;
        vector<pii>v;
        l=sz(s);
        loop0(i,l)
        {
            if(s[i]=='1') v.pb(pii(0,i));
            else vis[0][i]=1;
        }
        loop1(i,l-1)
        {
            cin>>s;
            loop0(j,l)
            {
                if(s[j]=='1') v.pb(pii(i,j));
                else vis[i][j]=1;
            }
        }
        int ans=0;
        loop0(i,sz(v))
        {
            if(!vis[v[i].ff][v[i].ss])
            {
                ans=max(ans,1+dfs(v[i].ff,v[i].ss));
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}

UVa – 10305 – Ordering Tasks

Arunima Mandal Leave a comment

Though this problem is solved by Topsort here, it can be also done by BFS.

#include <bits/stdc++.h>

#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector<int>
#define vll             vector<long long>
#define pii             pair<int,int>
#define pis             pair<int,string>
#define psi             pair<string,int>
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i<n;i++)
#define loop1(i,n)      for(int i=1;i<=n;i++)
#define stlloop0(i,x)   for(int i=0;i<x.size();i++)
#define stlloop1(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
#define case(z)         cout<<"Case "<<z<<": "
#define PI              3.14159265358979323846264338328
#define valid(nx,ny) nx>=0 && nx<r && ny>=0 && ny<c
#define MAX             2000

using namespace std;

vector<int>g[101],ans;
int indeg[101];

int main()
{
    CIN;
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);

    int node,edge;
    while(cin>>node>>edge)
    {
        if(node==0 && edge==0)
            break;
        ms(indeg,0);
        for(int i=0; i<edge; i++)
        {
            int from,to;
            cin>>from>>to;
            g[from].pb(to);
            indeg[to]++;
        }

        for(int i=1; i<=node; i++)
        {
            if(indeg[i]==0)
                ans.pb(i);
        }

        for(int i=0; i<ans.size(); i++)
        {
            int v=ans[i];
            for(int j=0; j<g[v].size(); j++)
            {
                int u=g[v][j];
                indeg[u]--;
                if(indeg[u]==0)
                    ans.pb(u);
            }
        }

        for(int i=0; i<ans.size(); i++)
            cout<<ans[i]<<" ";
        cout<<endl;
        for(int i=0; i<101; i++)
            g[i].clear();
        ans.clear();
    }
    return 0;
}

UVa – 280 – Vertex

Arunima Mandal Leave a comment 
#include <bits/stdc++.h>

#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector<int>
#define vll             vector<long long>
#define pii             pair<int,int>
#define pis             pair<int,string>
#define psi             pair<string,int>
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i<n;i++)
#define loop1(i,n)      for(int i=1;i<=n;i++)
#define stlloop0(i,x)   for(int i=0;i<x.size();i++)
#define stlloop1(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
#define case(z)         cout<<"Case "<<z<<": "
#define PI              3.14159265358979323846264338328
#define valid(nx,ny) nx>=0 && nx<r && ny>=0 && ny<c
#define MAX             2000

/*----------------------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
/*------------------------------------------------*/

using namespace std;

vector<int>g[MAX],ans;
bool visited[MAX];
int node;

void dfs(int u)
{
    int temp;
    for(int i=0; i<g[u].size(); i++)
    {
        temp=g[u][i];
        if(!visited[temp])
        {
            visited[temp]=1;
            dfs(temp);
        }
    }
}
int main()
{
    CIN;
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);

    while(cin>>node && node!=0)
    {
        int from,to;
        while(cin>>from && from!=0)
        {
            while(cin>>to && to!=0) g[from].pb(to);
        }
        int q;
        cin>>q;
        loop0(i,q)
        {
            int src;
            cin>>src;
            memset(visited,0,sizeof visited);
            dfs(src);
            int c=0;
            loop1(j,node)
            {
                if(visited[j]==0)
                {
                    c++;
                    ans.pb(j);
                }
            }
            cout<<c;
            stlloop0(k,ans) cout<<" "<<ans[k];
            cout<<endl;
            ans.clear();
        }
        loop0(i,MAX) g[i].clear();
    }
    return 0;
}

UVa – 11518 – Dominos 2

Arunima Mandal Leave a comment 
#include &lt;bits/stdc++.h&gt;

#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector&lt;int&gt;
#define vll             vector&lt;long long&gt;
#define pii             pair&lt;int,int&gt;
#define pis             pair&lt;int,string&gt;
#define psi             pair&lt;string,int&gt;
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i&lt;n;i++)
#define loop1(i,n)      for(int i=1;i&lt;=n;i++)
#define stlloop0(i,x)   for(int i=0;i&lt;x.size();i++)
#define stlloop1(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout&lt;&lt;"Case "&lt;&lt;i&lt;&lt;": "&lt;&lt;x&lt;&lt;endl
#define case(z)         cout&lt;&lt;"Case "&lt;&lt;z&lt;&lt;": "
#define PI              3.14159265358979323846264338328
#define valid(nx,ny) nx&gt;=0 &amp;&amp; nx&lt;r &amp;&amp; ny&gt;=0 &amp;&amp; ny&lt;c
#define MAX             10001

/*----------------------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
/*------------------------------------------------*/

using namespace std;

vector&lt;int&gt;g[MAX];
bool visited[MAX];
int node,edge;

void dfs(int u)
{
    visited[u]=1;
    int temp;
    for(int i=0; i&lt;g[u].size(); i++)
    {
        temp=g[u][i];
        if(!visited[temp]) dfs(temp);
    }
}
int main()
{
    CIN;
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);
    int t;
    cin&gt;&gt;t;
    loop1(z,t)
    {
        int l;
        cin&gt;&gt;node&gt;&gt;edge&gt;&gt;l;
        for(int i=0; i&lt;edge; i++)
        {
            int from,to;
            cin&gt;&gt;from&gt;&gt;to;
            g[from].push_back(to);
        }
        loop0(i,l)
        {
            int src;
            cin&gt;&gt;src;
            dfs(src);
        }
        int c=0;
        loop1(i,node)
        {
            if(visited[i]==1) c++;
        }
        cout&lt;&lt;c&lt;&lt;endl;
        memset(visited,0,sizeof visited);
        loop0(i,MAX) g[i].clear();
    }
    return 0;
}

UVa – 439 – Knight Moves

Arunima Mandal Leave a comment 
#include <bits/stdc++.h>

#define ms(a,b)         memset(a,b,sizeof(a))
#define pb(a)           push_back(a)
#define db              double
#define ft              float
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define sz(x)           x.size()
#define qu              queue
#define pqu             priority_queue
#define vc              vector
#define vi              vector<int>
#define vll             vector<long long>
#define pii             pair<int,int>
#define pis             pair<int,string>
#define psi             pair<string,int>
#define all(x)          x.begin(),x.end()
#define CIN             ios_base::sync_with_stdio(0); cin.tie(0)
#define loop0(i,n)      for(int i=0;i<n;i++)
#define loop1(i,n)      for(int i=1;i<=n;i++)
#define stlloop(x)     for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)
#define gcd(a, b)       __gcd(a, b)
#define lcm(a, b)       ((a)*((b)/gcd(a,b)))
#define case(z,x)       cout<<"Case "<<i<<": "<<x<<endl
#define case(z)         cout<<"Case "<<z<<": "
#define PI              3.14159265358979323846264338328
#define valid(tx,ty)    tx>=1 && tx<=row && ty>=1 && ty<=col
#define MAX             2000

/*----------------------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

/*------------------------------------------------*/

using namespace std;

int fx[]= {-2, -2, -1, -1,  1,  1,  2,  2}; // Knights Move
int fy[]= {-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
bool vis[10][10];
int dis[10][10];
//int cell[1002][1002]; // if cell[x][y]=-1 , then the cell is block
int row=8,col=8;
map<char,int> mp1,mp2;

int bfs2d(int sx,int sy,int dx,int dy) //Source node is in [sx][sy] cell & dest node is in [dx][dy] cell.
{
    dis[sx][sy]=0;
    ms(vis,0);
    vis[sx][sy]=1;
    qu<pii> q;
    q.push(pii(sx,sy));
    while(!q.empty())
    {
        pii top=q.front();
        q.pop();
        if(top.ff==dx && top.ss==dy) return dis[dx][dy];
        for(int k=0; k<8; k++)
        {
            int tx=top.ff+fx[k];
            int ty=top.ss+fy[k]; //Neighbor cell [tx][ty]
            if(valid(tx,ty) and vis[tx][ty]==0) //Check if the neighbor is valid and not visited before.
            {
                vis[tx][ty]=1;
                dis[tx][ty]=dis[top.ff][top.ss]+1;
                q.push(pii(tx,ty)); //Pushing a new pair in the queue
            }
        }
    }
    return -1;
}
int main()
{
    CIN;
    string s,t;
    while(cin>>s>>t)
    {
        cout<<"To get from "<<s<<" to "<<t<<" takes "<<bfs2d(s[0]-'a'+1,s[1]-'0',t[0]-'a'+1,t[1]-'0')<<" knight moves."<<endl;
    }
    return 0;
}