gistfile1.txt

G = {}

G[(1,2,3)] = [(1,2,2), (1,2,3), (0,2,3),
              (2,2,2), (1,3,2), (2,1,3)]



def next_states(S):
    r = []
    
    if 0<S[2]:
        r.append((S[0],S[1]+1,S[2]-1))
        r.append((S[0]+1,S[1],S[2]-1))
        r.append((S[0],S[1],S[2]-1))

    if 0<S[1]:
        r.append((S[0]+1,S[1]-1,S[2]))
        r.append((S[0],S[1]-1,S[2]))
        
    if 0<S[0]:
        r.append((S[0]+1,S[1],S[2]))
        
    return r

def build_graph():
    
    G = {}

    states = [(0,N,M)]
    
    while True:

        s = states[i]

        ss = next_states(s)

        for s1 in ss:
            if s1 in G:
                pass
            else:
                G[s].append(s1)

            
    return G