我写一版,供你参考
m = {}
n = int(input())
for i in range(n):
line = input()
l2 = line.split()
for l in l2[1:]:
m[l] = m.get(l, 0) + 1
a1 = sorted(m.items(), key=lambda x: x[1], reverse=True)
max_num = a1[0][1]
print("兴趣:", end=" ")
for a in a1:
if a[1] >= max_num:
print(a[0], end=" ")
从大到小排序,然后从头开始挨个判断,只要和第一个一样的都输出,直到遇到不一样的