teams = [“a”,“b”,“c”,“d”]
count = 0
for i in range(len(teams)):
for j in range(len(teams)):
if j == i:
break
else:
count += 1
print(str(teams[j]) + " vs " + str(teams[i]))
print(“4支球队在单循环赛制下总共打”+str(count)+“场比赛”)