Assignment 7

'''
1.A program, which uses recursion to calculate the sum of values between n and m, where n and m can be any integer number.
2.A program which uses recursion to calculate the sum of n values of this series: 1/5, 1/8, 1/11,...,1/(3n+2).
3.A program, which uses recursion to find all indexes of a substring (substr) in a string (str).
4.A program which uses lambda operator and map() function to convert each value x in this list: [25,39,52,68,20,89] to a new value y according to these conditions: if x<50, y=0 if 50<x<=75, y=2, if x>75, y=3.
5.A program which uses filter() to filter out values less than 50 in this list: [25,39,52,68,20,89].
6.A program, which uses reduce() function to calculate the greatest value in this list:  [25,39,52,68,20,89].
'''
def q1():
    n=input('Please type a value for n:')
    m=input('Please type a value for m:')
    a=0;b=0;s=0;c=abs(eval(n)-eval(m))
    if eval(n)>eval(m):
        a=eval(m)
    else:
        a=eval(n)
    for i in range(1,c):
        b=a+i
        s+=b
    print(s)
def q2():
    a=2;s=0
    for i in range(10):
        a+=3*i
        b=1/a
        s+=b
    print(s)
def q3():
    string='Hello world!'
    for i in range(len(string)):
        print('The index of',string[i],'is: ',i)
def q4():
    li=[25,39,52,68,20,89]
    s=lambda x: 0 if x < 50 else 2 if x > 50 and x<=75 else 3 if x>=75 else None
    print(list(map(s,li)))
def q5():
    li=[25,39,52,68,20,89]
    s=lambda x:x<50
    print(list(filter(s,li)))
def q6():
    import functools
    li=[25,39,52,68,20,89]
    s=lambda x,y:x if x>y else y
    print(functools.reduce(s,li))

text=input('Please give the sequence number of question you want to test:')
a=eval(text)
if a==1:
    q1()
elif a==2:
    q2()
elif a==3:
    q3()
elif a==4:
    q4()
elif a==5:
    q5()
elif a==6:
    q6()
else:
    print('The question number shouble be between 1 and 6.')