实验四

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) )
#3
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))
#2
list1 = [1, 9, 8, 4]
print( sorted(list1) )
print( sorted(list1, reverse=True) )

 

 

def solve(a, b, c):
    '''
    求解一元二次方程, 返回方程的两个根
    :para: a,b,c: int 方程系数
    :return: tuple
    '''
    delta = b*b - 4*a*c
    delta_sqrt = abs(delta)**0.5
    p1 = -b/2/a
    p2 = delta_sqrt/2/a
    if delta>=0:
        r1 = p1 + p2
        r2 = p1 - p2
    else:
        r1 = complex(p1, p2)
        r2 = complex(p1, -p2)
    return r1, r2

print(solve.__doc__)
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:
                r1, r2 = solve(a, b, c)
                print(f'r1 = {r1:.2f}, r2 = {r2:.2f}')
                print(

 

 

 

 

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


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

 

 

def is_prime(x):
    for i in range(2,int(x)):
        if x % i == 0:
            break
            return False
    else:
        return True

for i in range(2, 21, 2):
    for w in range(2, i):
        if is_prime(i - w)==True and is_prime(w)==True:
            print(f"{i} = {w} + {i-w}")
            break

 

 

def encoder(text):
    list = []
    for i in text:
        if 97<=ord(i)<=118 or 65<=ord(i)<=86:
            t=chr(ord(i)+5)
            list.append(t)
        elif i==',':
            t=','
            list.append(t)
        elif i == ' ':
            t = ' '
            list.append(t)
        else:
            t=chr(ord(i)-21)
            list.append(t)
    return ''.join(list)
def decoder(text):
    list = []
    for i in text:
        if 101<= ord(i) or 69<=ord(i)<=90:
            t = chr(ord(i)-5)
            list.append(t)
        elif i==',':
            t=','
            list.append(t)
        elif i==' ':
            t=' '
            list.append(t)
        else:
            t = chr(ord(i) + 21)
            list.append(t)
    return ''.join(list)
a=input(':')
print(encoder(a))
b=input(':')
print(decoder(b))

 

 

 

 

def collatz(x):
    if x%2==0:
        return x/2
    else:
        return 3*x+1
try:
    s=0
    while s==0:
        a=eval(input(":"))
        list=[a]
        a=collatz(a)
        while True:
            if a!=1:
                list.append(a)
                a=collatz(a)
                continue
            else:
                list.append(a)
                break
        print(list)
except:
    print('Error: must be a positive integer')