Problem Set 2 Solution

xxxxxxxxxx
sentence = "My email address is wang.lu@mail.shufe.edu.cn It was created on 1st Sept. 2017 Friday"
count = 0 
for letter in sentence:
    if letter == "e":
        count = count +1
print(count)
index_1 = sentence.find('@')
index_2 = sentence.find(' ', index_1)
host = sentence[index_1+1: index_2]
print(host)
index_3 = sentence.find('on')
t = sentence[index_3+2:]
date = t.split()
print(date)

xxxxxxxxxx
info = dict()
info['Mike']=['Java', 25]
info['Tracy']=['C++', 21]
info['Jack']=['Python', 19]
name = list(info.keys())
name.sort()
for x in name:
    print(x, info[x][0],info[x][1])

x
for x in range(1, 10):
    for y in range(1, x+1):
        print(str(x)+'*'+str(y)+'='+str(x*y),end=' ')
    print()

xxxxxxxxxx
def fib(n):
    if n==1:
        print(1)
    elif n==2:
        print(1,1)
    elif n>2:
        print(1,1,end=" ")
    count = 0
    n1 = 1
    n2 = 1
    while count < n-2:
        nth = n1 + n2
        print(nth,end=" ")
        n1 = n2
        n2 = nth
        count = count + 1

x
def noDuplicates(x):
    z={}
    for letter in x:
        z[letter]=z.get(letter,0)+1
    m = ""
    for n in z.keys():
        m=m+n
    return m

x
def noDuplicates(x):
    z = {}
    for tri in x:
        letter = tuple(sorted(tri))
        z[letter]=z.get(letter,0)+1
    m = []
    for n in z.keys():
        m.append(list(n))
    return m

def threeSum(x):
    i=len(x)
    y=[]
    for j in range(i):
        for k in range(j+1,i):
            for l in range(k+1,i):
                if x[j]+x[k]+x[l]==0:
                    y.append([x[j],x[k],x[l]])
    return noDuplicates(y)

y=[-1,0,1,2,-1,-4,6,-2]
print(threeSum(y))