Java - Algorithm to find most connected numbers [closed]

Answer 1

First find a non-visited cell, and start recursion. disclaimer: This is not java, it's pseudo C without most declarations and headers. C is anyway much easier to convert to java... Use a global or a class member for the count if necessary.

To make things easier, surround your N*N array by guards.

    // with -1 -1 -1 -1 
    //      -1  x  x -1
    //      -1 -1 -1 -1

for (i=N+2;i<(N+2)*(N+1);i++) { // exact starting and ending locations are disclosed
  if (k=array[i]!=-1) {
      j=1;
      flood_fill(array,i,k,&j);
      if (j>max) { max=j; max_number=k; }
  }
}

#define UP -(N+2)
#define DOWN (N+2)
#define LEFT -1
#define RIGHT 1

int flood_fill(int *array, int position, int value_to_compare, int *count)
{
    // for each direction UP,DOWN,RIGHT,LEFT 
    static const int directions[4]={UP,DOWN,RIGHT,LEFT];
    int t;
    for (t=0;t<4;t++)
    if (array[position + directions[t]]==value_to_compare) {
        array[position + directions[t]] = -1;
        *count+=1;
        flood_fill(array, position+directions[t], value_to_compare, count);
    }
}