实验4

print(sum)
sum = 42
print(sum)

def inc(n):
    sum = n+1
    print(sum)
    return sum
sum = inc(7) + inc(7)
print(sum)

def func1(a, b, c, d, e, f):
    return [a,b,c,d,e,f]

def func2(a, b, c,*, d, e, f):
    return [a,b,c,d,e,f]

def func3(a, b, c, /, d, e, f):
     return [a,b,c,d,e,f]


print( func1(1,9,2,0,5,3) )
print( func1(a=1, b=9, c=2, d=0, e=5, f=3) )
print( func1(1,9,2, f=3, d=0, e=5))


print( func2(11, 99, 22, d=0, e=55, f=33) )
print( func2(a=11, b=99, c=22, d=0, e=55, f=33) )


print( func3(111, 999, 222, 0, 555, 333))
print( func3(111, 999, 222, d=0, e=555, f=333))

list1 = [1, 9, 8, 4]

print( sorted(list1) )
print( sorted(list1, reverse=True) )
print( sorted(list1, True) )

def func(a, b, c, /, *, d, e, f):
    return( [a,b,c,d,e,f] )

print(func(1,2,3,d=4,e=5,f=6))

def solve(a, b, c):
    delta = b*b - 4*a*c
    delta_sqrt = abs(delta)**0.5
    p1 = -b/2/a;
    p2 = delta_sqrt/2/a
    if delta>=0:
        root1 = p1 + p2
        root2 = p1 - p2
    else:
        root1 = complex(p1, p2)
        root2 = complex(p1, -p2)

    return root1, root2



while True:
    try:
        a,b,c = eval(input('Enter eqution coefficient: '))
        if a == 0:
            raise
    except:
        print('invalid input, or, a is zero')
        break
    else:
        root1, root2 = solve(a, b, c)
        print(f'root1 = {root1:.2f}, root2 = {root2:.2f}')
        print()

def is_prime(n):
    if n==2:
        return True
    else:
        a=2
        for i in range(2,n):
            if n%i==0:
                return False
            else:
                a=a+1
                if a==n:
                    return True
list1=[]
list2=[]
for i in range(1,21):
    if is_prime(i)==True:
        list1.append(i)
    elif is_prime(i)==False:
        list2.append(i)
for i in range(len(list2)):
    z=1
    x=0
    y=0
    while z!=0:
        if int(list2[i])==int(list1[x])+int(list1[y]):
            print(list2[i],'=',list1[x],'+',list1[y])
            z=0
        else:
            y=y+1
            if y==7:
                x=x+1
                y=x

z=0
x=str(input('输入英文文本：'))
for i in range(len(x)):
    if 128>ord(x[i])+5>122 or 96>ord(x[i])+5>90:
        a=ord(x[i])-21
        z=z+1
    elif 65<=ord(x[i])<=85 or 97<=ord(x[i])+5<=117:
        a=ord(x[i])+5
        z=z+1
    else:
        a=ord(x[i])
        z=z+1
    if z==1:
        print('编码后的文本',end='')
    print(chr(a),end='')
print()
print('对编码后的文本解码',x)

def collatz(a):
    l=[a]
    while l[-1] != 1:
        if l[-1] % 2 == 0 :
            l.append((l[-1])//2)
        else:
            l.append((l[-1])*3+1)
    return l

try:
    x=int(input('enter a positive integer:'))
    if x <= 0:
        raise
except:
    print('Error: must be a positive integer')
else:
    print(collatz(x))

 

 

def list_generator(x,y,s=1):
    l=[]
    while x<=y :
        l.append(x)
        x=x+s
    return l

list1 = list_generator(-5, 5)
print(list1)
list2 = list_generator(-5, 5, 2)
print(list2)
list3 = list_generator(1, 5, 0.5)
print(list3)