Question

def count_neighbors(cells, row, col):

• Return value: An integer; the number of "alive" neighbors that the cell in the given row and column has.

• Assumptions: cells will be a two-dimensional list with at least one row and one element in that row.

• Notes: The tests for this function are hidden. Be careful: row or column may not be valid (return -1 if so)

• Examples:

count_neighbors([[0,0,0],[0,1,0],[0,0,0]],1,1) → 0

count_neighbors([[0,1,0,0],[0,1,0,1],[1,1,0,1]],2,1) → 3

count_neighbors([[0,0,0],[0,1,0],[0,0,0]],-1,1) → -1

Answer 1

Note

######

Index is considered to be starting from 0 ie if the array is 3 *4 size then

                     row index will be 0 to 2

                   column index will be 0 to 3

##################### PGM START ###########################################

#method to find the neighbours which are alive
def count_neighbors(cells, row, col):
    count=0
  
    #check if the row and col values are valid, if not return -1
    if(not((row>=0 and row<len(cells)) and (col>=0 and col<len(cells[row])))):
        return -1

    #check for all the 8 neighbours, if values are 1 incremnt counter by 1
    if row-1>=0 and (cells[row-1][col]==1):
        count+=1
      
    if (row+1<len(cells)) and (cells[row+1][col]==1):
        count+=1
          
    if (col-1>=0) and (cells[row][col-1]==1):
        count+=1
      
    if (col+1<len(cells[row])) and (cells[row][col+1]==1):
        count+=1
      
    if (col+1<len(cells[row]) and row+1<len(cells)) and (cells[row+1][col+1]==1):
        count+=1
      
    if (col+1<len(cells[row]) and row-1>=0) and (cells[row-1][col+1]==1):
        count+=1
      
    if (row+1<len(cells) and col-1>=0) and (cells[row+1][col-1]==1):
        count+=1
      
    if (col-1>=0 and row-1>=0) and (cells[row-1][col-1]==1):
        count+=1
  
    #return final count
    return count

#main method
if __name__=="__main__":
    print(count_neighbors([[0,0,0],[0,1,0],[0,0,0]],1,1))
    print(count_neighbors([[0,1,0,0],[0,1,0,1],[1,1,0,1]],2,1))
    print(count_neighbors([[0,0,0],[0,1,0],[0,0,0]],-1,1))
    print(count_neighbors([[1,1,1,1],[1,1,1,1],[1,1,1,1]],1,2))
   

####################### PGM END ###########################################

OUTPUT
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