有向图最短路径floyd算法的python实现

Created on 2012-11-8@author: Pandara'''import sysdef floyd(l, n):    '''    l: l[i][j] = distace of i and j if <i, j> in E else sys.maxint    k: sum of point    '''    d = l[:]        route = [([''] * n) for i in range(n)]    for i in range(n):        for j in range(n):            if d[i][j]:                route[i][j] = str(i + 1) + " " + str(j + 1)        for k in range(n):        for i in range(n):            for j in range(n):                if d[i][j] > d[i][k] + d[k][j]:                    d[i][j] = d[i][k] + d[k][j]                    route[i][j] = route[i][k] + " " + route[k][j][2:]    return d, routeif __name__ == "__main__":    n = 3    l = [[0, 2, 9], [8, 0, 6], [1, sys.maxint, 0]]    d, route = floyd(l, n)        for i in d:        for j in i:            print j,        print ""        for i in route:        for j in i:            print "[" + j + "],",        print ""