MaxDonchenko

Goldbach's conjecture is one of the oldest and best-known unsolved problems in number theory and all of mathematics. It states:

Every even integer greater than 2 can be expressed as the sum of two primes.
For example: 

`6 = 3 + 3`</br>
`8 = 3 + 5`</br>
`10 = 3 + 7 = 5 + 5`</br>
`12 = 5 + 7`

MaxDonchenko

def get_col_name(col):
    abc = " ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    col_name = ""
    while col > 0:
        letter_index = col % 26
        if letter_index == 0:
            letter_index = 26
            col -= 26
        col //= 26
        col_name = abc[letter_index] + col_name

MaxDonchenko

class Vertex:

    def __init__(self, name, value=1, connections={}):
        self.name = name
        self.value = value
        self.connections = connections

    def __repr__(self):
        return "%s(%d)" % (self.name, self.value)

MaxDonchenko

graph = {'A': set(['B', 'C']),
         'B': set(['A', 'D', 'E']),
         'C': set(['A', 'F']),
         'D': set(['B']),
         'E': set(['B', 'F']),
         'F': set(['C', 'E'])}

def dfs_paths(graph, start, goal):
    stack = [(start, [start])]
    while stack: