1.
# coding=utf-8
#用*打印实心正方形
import sys
n=input("输入数字：")
for i in range(0,int(n)):
print("* "*n)
2.
# coding=utf-8
#找出重复的名字
import sys
class1=['John','Bill','NiKi','Mark','Mark','Bill']
class2=['Bill','NiKi','Linda']
same = set(class1)&set(class2)
print(same)
# coding=utf-8
#找出重复的名字
import sys
num1=int(input("输入班级1学生数量："))
class1=set()
for i in range(0,num1):
name =input('输入学生姓名%d姓名：'%(i+1))
class1.add(name)
num2=int(input("请输入班级2学生数量："))
class2=set()
for i in range(0,num2):
name = input('输入学生姓名%d姓名：'%(i+1))
class2.add(name)
same=class1&class2
for name in same:
print(name)
3.
# coding=utf-8
#找出在class2中出现但是不在class1中的名字
#交集：&/intersection
#并集：｜/union
#差集：-/different
import sys
num1=int(input("输入班级1学生数量："))
class1=set()
for i in range(0,num1):
name =input('输入学生姓名%d姓名：'%(i+1))
class1.add(name)
num2=int(input("请输入班级2学生数量："))
class2=set()
for i in range(0,num2):
name = input('输入学生姓名%d姓名：'%(i+1))
class2.add(name)
diffcl2=class2-class1
for name in diffcl2:
print(name)
