Graph

import random

def rand_gr(n,m):

  ts=[]

  sr=[]

  for i in range(n):

    ts.append([0]*n)

  if m>n*(n-1)/2:

    return

  for i in range(m):

    j=random.randint(0,n-2)

    k=random.randint(j+1,n-1)

    z=random.randint(1,20)

    while ts[j][k]==1:

      j=random.randint(0,n-2)

      k=random.randint(j+1,n-1) 

    ts[j][k]=z

    ts[k][j]=z

    sr.append([j,k,z])

  return(ts,sr)

n=3

m=3

table1, rib=rand_gr(n,m)

def to_table(n,rib):

  ts1=[]

  for i in range(n):

    ts1.append([0]*n)

  for i in range (len(rib)):

    ts1[rib[i][0]][rib[i][1]]=rib[i][2]

    ts1[rib[i][1]][rib[i][0]]=rib[i][2]

  return(ts1)

def to_rib(n,table1):

  sr1=[]

  for i in range(n):

    for j in range(i+1,n):

      if table1[i][j]!=0:

        sr1.append([i,j,table1[i][j]])

  return(sr1)