[算法导论]BFS @ Python
class Graph: def __init__(self): self.V = [] class Vertex: def __init__(self, x): self.key = x self.color = 'white' self.d = 10000 self.pi = None self.adj = [] class Solution: def BFS(self, G, s): for u in G.V: if u != s: u.color = 'white' u.d = 10000 u.pi = None s.color = 'gray' s.d = 0 s.pi = None Q = [] Q.append(s) while Q != []: u = Q.pop(0) for v in u.adj: if v.color == 'white': v.color = 'gray' v.d = u.d + 1 v.pi = u Q.append(v) u.color = 'black' if __name__ == '__main__': G = Graph() r = Vertex('r') s = Vertex('s') t = Vertex('t') u = Vertex('u') v = Vertex('v') w = Vertex('w') x = Vertex('x') y = Vertex('y') r.adj = [s, v] s.adj = [r, w] t.adj = [u, w, x] u.adj = [t, x, y] v.adj = [r] w.adj = [s, t, x] x.adj = [t, u, w, y] y.adj = [u, x] G.V = [r, s, t, u, v, w, x, y] m = Solution() m.BFS(G, s) for v in G.V: if v != s: print v.key, v.color, v.d, v.pi.key