2018校招算法工程师

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抛砖引玉

2018阿里校招笔试

Question 1

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import numpy as np
N = 9
intersections = np.array([[0,3],[1,5],[2,7],[3,3],[4,5],[5,7],[6,9],[7,3],[8,5]])
M = 14
roads = np.array([[0,1,4],[0,7,8],[1,2,8],[1,7,11],[2,3,7],[2,5,4],[2,8,2],[3,4,9],[3,5,14],[4,5,10],[5,6,2],[6,8,6],[6,7,1],[7,8,7]])
s = 0
t = 4
def WaitTime(CurrentTime,permision):
    if CurrentTime % (2*permision) in [x for x in range(permision)]: # Green light
        return 0
    else:
        return (2*permision) - CurrentTime % (2*permision)
    
def CanGo(source):
    NodeWithTime = {}
    for i in range(len(roads[roads[:,0] == source])):
        NodeWithTime[roads[roads[:,0] == source][i,1]] = roads[roads[:,0] == source][i,2]
    for i in range(len(roads[roads[:,1] == source])):
        NodeWithTime[roads[roads[:,1] == source][i,0]] = roads[roads[:,1] == source][i,2]    
    return NodeWithTime
    
    
def minTravelTime(N,intersections,M,roads,s,t):
    Nodes = [s]
    A = {}
    A[s] = 0
    
    for source in Nodes:
        permision = intersections[source][1]         
        NodeWithTime = CanGo(source)
        for determination in NodeWithTime.keys():
            value = A[source] + WaitTime(A[source],permision) + NodeWithTime[determination]
            if determination in A.keys():                    
                A[determination] = min(value,  A[determination])
            else:
                A[determination] = value
            if determination not in Nodes:
                Nodes.extend([determination])
        #print Nodes
        #print A      
    return A[t]                           
print minTravelTime(N,intersections,M,roads,s,t)
# 28

Question 2

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def number(k):
    count = 1
    iteration = 1
    while count < k:
        count += iteration +1
        iteration += 1
        
    startposition = count - iteration 
    return k - startposition

2018 京东笔试

Question 1

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def calc(n):
    count = 1
    while count < k:
        count += iteration +1
        iteration += 1
    return iteration

80%

Question 2

brute force
20%
try

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def calc(n):
    if n == 1:
        return 1
    else: 
        sum = n*n
        for a in range(2,n+1):
            for b in range(1,n+1):
                if (a**b < n) and (a**(b+1) > n):
                    for i in range(1, b+1):
                        sum += i*n/(b)
                elif a**b == n:
                    sum += n
        return sum

2018 didi

1

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#coding = utf-8
import sys
if __name__ == "__main__":
    # 读取第一行的n
    n = int(sys.stdin.readline().strip())
    line = sys.stdin.readline().strip()
    # 把每一行的数字分隔后转化成int列表
    values = map(int, line.split())
    #values.sort()
    value_set = set(values)
    count = 0
    for i in value_set:
        values.remove(i)
        if i in values:
            count += 1
        elif i == 0:
            count += 1
    
    print count

2

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#coding = utf-8
import sys
if __name__ == "__main__":
    # 读取第一行的n
    n = int(sys.stdin.readline().strip())
    if n == 1:
        print 1
    a = [2,3,5]
    while True:
        for i in range(len(a)):
            for j in range(len(a)):
                result = a[i] * a[j]
                if result < a[-1]:
                    a.append(result)
                    a.sort()

头条

1

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#coding = utf-8
import sys
if __name__ == "__main__":
    # 读取第一行的n
    first_line = map(int,sys.stdin.readline().strip().split())
    n = first_line[0]
    m = first_line[1]
    c = first_line[2]
    dicti = {}
    for i in range(n):
        # 读取每一行
        line = sys.stdin.readline().strip()
        # 把每一行的数字分隔后转化成int列表
        values = map(int, line.split())
        if len(values) > 1:
            dicti[tuple(values[1:])] = i+1
        else:
            dicti[tuple()] = i+1
    sth = {}
    for i in range(1,c+1):
        a = []
        for keys in dicti.keys():
            if i in keys:
                a += dicti[keys]
        sth[i] = a+a
    count = 0
    for key, value in sth.iteritems():
        for i in range(len(value)-1):
            if ((value[i]+m) % n) > value[i+1]:
                count += 1
    print count

2

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#coding = utf-8
import sys
if __name__ == "__main__":
    # 读取第一行的n
    n = int(sys.stdin.readline().strip())
    second_line = map(int,sys.stdin.readline().strip().split())
    check_num = int(sys.stdin.readline().strip())
    
    for i in range(check_num):
        # 读取每一行
        line = sys.stdin.readline().strip()
        # 把每一行的数字分隔后转化成int列表
        values = map(int, line.split())
        count = 0
        sth = second_line[values[0]-1:values[1]]
        while values[2] in sth:
            count += 1
            sth.remove(values[2])
        print count

科大讯飞

1

0.8

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people = raw_input()
count = 0
while len(people) != 0:
    if people[0] == 'L':
        count += 1
        people = people[1:]
        print people
    else:
        if 'L' in people:
            L_index = people.index('L')
            if (L_index + 1) < (len(people) - 1):
                people = 'R'+people[L_index+1:]
                print people
            else:
                people = 'R'
                print people
        else:
            print people
            count += len(people)
            break
print people
print count

2

0.4

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n = raw_input()
course = []
dicti = {}
repeat_key = []
for i in range(int(n)):
    line = raw_input()
    course += [line.split()]
    #print 'course'+str(course)
    if course[i][0] in dicti.keys():
        repeat_key += [course[i][0]]
        #print 'dicti[course[i][0]]'+str(dicti[course[i][0]])
        #print '[course[i][1]]'+str([course[i][1]])
        dicti[course[i][0]] += [course[i][1]]
    else:
        dicti[course[i][0]] = [course[i][1]]
#print course
#print dicti
#print repeat_key
if len(repeat_key) == 0:
    print 'YES'
else:
    repeat_key.sort()
    for i in repeat_key:
        print i +' '+ ' '.join(dicti[i])

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01 204521
23 204523
22 204526
01 204528
22 204527
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11 204521
23 204522
43 204531

3

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n = raw_input()
name = []
for i in range(int(n)):
    group = raw_input()
    name += [group]

souhu

1

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f_l = raw_input()
arr = f_l.split('/')
path = []
for i in range(len(arr)):
    
    if arr[i] == '.':
        pass
    elif arr[i] == '..':
        path.pop()
    else:
        path += [arr[i]]
sth = '/'.join(path)
sth = sth[:-1]
print sth

2

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f_l = raw_input()
n = int(f_l)
s_l = raw_input()
arr = map(int, s_l.split(' '))
# print s_l
#print arr
count = 0
while len(arr) > 1:
    if arr[0] < arr[-1]:
        count += arr[0]*2
        #print count
        arr.pop(0)
        
    elif arr[0] > arr[-1]:
        count += arr[-1]*2
        #print count
        arr.pop(-1)
    else:
        count += arr[0]*2
        #print count
        arr.pop(0)
        arr.pop(-1)
if len(arr) == 0:
    print count
else:
    print count+arr[0]

美的

1 文件中不重复的url

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def get_next_target(page):
    start_link = page.find('http')
    if start_link == -1:
        return None, 0
    start_quote = page.find('http', start_link)
    end_quote = page.find('http', start_quote + 1)
    url = page[start_quote + 1:end_quote]
    return url, end_quote
def union(a, b):
    if b not in a:
        a.append(b)
        
def get_all_links(page):
    links = []
    while True:
        url, endpos = get_next_target(page)
        if url:
            union(links,url)
            page = page[endpos:]
        else:
            break
    return links
file_path = "G:\intro to DA\Data Wrangling with MongoDB - Udacity.html"
HtmlFile = open(file_path, 'r')
context = HtmlFile.read()  # type: string
links = get_all_links(context)
HtmlFile.close()
urlfile = open('URL.txt', 'w')
for url in links:
    url.write("%s\n" % item)
urlfile.close()

2 实现前向传播算法

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import numpy as np
def layer_sizes(X, Y):
    """
    Arguments:
    X -- input dataset of shape (input size, number of examples)
    Y -- labels of shape (output size, number of examples)
    
    Returns:
    n_x -- the size of the input layer
    n_h -- the size of the hidden layer
    n_y -- the size of the output layer
    """
    
    n_x = X.shape[0] # size of input layer
    n_h = 4
    n_y = Y.shape[0] # size of output layer
    
    return (n_x, n_h, n_y)
def initialize_parameters(n_x, n_h, n_y):
    """
    Argument:
    n_x -- size of the input layer
    n_h -- size of the hidden layer
    n_y -- size of the output layer
    
    Returns:
    params -- python dictionary containing your parameters:
                    W1 -- weight matrix of shape (n_h, n_x)
                    b1 -- bias vector of shape (n_h, 1)
                    W2 -- weight matrix of shape (n_y, n_h)
                    b2 -- bias vector of shape (n_y, 1)
    """
    
    np.random.seed(2) # we set up a seed so that your output matches ours although the initialization is random.
    
    
    W1 = np.random.randn(n_h,n_x) * 0.01
    b1 = np.zeros((n_h,1))
    W2 = np.random.randn(n_y,n_h) * 0.01
    b2 = np.zeros((n_y,1))
    
    
    assert (W1.shape == (n_h, n_x))
    assert (b1.shape == (n_h, 1))
    assert (W2.shape == (n_y, n_h))
    assert (b2.shape == (n_y, 1))
    
    parameters = {"W1": W1,
                  "b1": b1,
                  "W2": W2,
                  "b2": b2}
    
    return parameters
def forward_propagation(X, parameters):
    """
    Argument:
    X -- input data of size (n_x, m)
    parameters -- python dictionary containing your parameters (output of initialization function)
    
    Returns:
    A2 -- The sigmoid output of the second activation
    cache -- a dictionary containing "Z1", "A1", "Z2" and "A2"
    """
    # Retrieve each parameter from the dictionary "parameters"
    
    W1 = parameters["W1"]
    b1 = parameters["b1"]
    W2 = parameters["W2"]
    b2 = parameters["b2"]
    
    
    # Implement Forward Propagation to calculate A2 (probabilities)
    
    Z1 = np.dot(W1, X) + b1
    A1 = np.tanh(Z1)
    Z2 = np.dot(W2, A1) + b2
    A2 = sigmoid(Z2)
    
    
    assert(A2.shape == (1, X.shape[1]))
    
    cache = {"Z1": Z1,
             "A1": A1,
             "Z2": Z2,
             "A2": A2}
    
    return A2, cache
n_x = layer_sizes(X, Y)[0]
n_y = layer_sizes(X, Y)[2]
# Initialize parameters, then retrieve W1, b1, W2, b2. Inputs: "n_x, n_h, n_y". Outputs = "W1, b1, W2, b2, parameters".
parameters = initialize_parameters(n_x, n_h, n_y)
W1 = parameters["W1"]
b1 = parameters["b1"]
W2 = parameters["W2"]
b2 = parameters["b2"]
A2, cache = forward_propagation(X, parameters)

3

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```
# Face ++
25%
改进未完成
```python
f = True
while f:
    s_n = raw_input()
    n = int(s_n)
    if n == -1:
        break
    else:
        s = 0
        s_f = 0.0
        for i in range(n):
            s1 = raw_input()
            if '.' in s1:
                s_li = s_f.split('.')
                s_l, s_r = long(s_li[0]), long(s_li[1])
                
                li = s1.split('.')
                left, right = long(li[0]), long(li[1])
                
                lll = s_l + left
                rrr = s_r + right
                
                n1 = float(s1)
            else:
                n1 = int(s1)
            s += n1
        print s

baidu

1

当时未完成

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s_n = raw_input()
n = int(s_n)
def f(n):
    lis = [2,3,5,7]
    lis_d = []
    for i in range(1,6):
        lis_i = []
        for j in range(10**i,10**(i+1)):
            
            lis_ = lis[:]
            fl = []
            for k in lis_:
                if j % k == 0:
                    fl.append(True)
                    break
            if True not in fl:
                lis_i.append(j)
                lis.append(j)
                
        #print 'lis_i: ' + str(lis_i)
        
        lis__ = lis_i[:]
        if len(lis__) > 0:
            for ii in lis__:
                s_ii = str(ii)
                r_s_ii = s_ii[::-1]
                r_ii = int(r_s_ii)
                if r_ii != ii and r_ii in lis__:
                    lis_d.append(ii)
                    if len(lis_d) == n:
                        return lis_d
print f(n)

小红书

1

90%

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s = raw_input()
f = True
num = len(s) / 3
ss =  s.replace("RED", "", num)
li = '1234567890'
max_n = -1
s_n = ''
for i in range(len(ss)):
    si = ss[i]
    if si in li:
        f = False
        s_n += si
        n = int(s_n)
        if n > max_n:
            max_n = n
    else:
        s_n = ''
if max_n > 0:
    print max_n    
if f:
    print -1

2

stay stuned.

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s = raw_input()
mo = s_mo.split(' ')
n_mo = map(int, mo)
a,b,n = n_mo[0], n_mo[1], n_mo[2]
ss = ['r','e','d']
ite = ss[:]
for i in range(n):
    l_re = []
    for j in ss:
        for k in ite:
            re = j + k
            l_re.append(re)
    ss = l_re[:]
#judge
for i in range(len(ss)):
    ch = ss[i]
    ch.replace('r','1',len(ss))
    ch.replace('e','0',len(ss))
    ch.replace('d','0',len(ss)

3

80%

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s_n = raw_input()
n = int(s_n)
s_mo = raw_input()
mo = s_mo.split(' ')
n_mo = map(int, mo)
# print n_mo
s_sum = raw_input()
sum_ = int(s_sum)
li = n_mo[:]
count = 1
if sum_ in li:
    print 1
else:    
    while min(li) < sum_:
        l_re = []
        for i in li:
            for j in n_mo:
                re = i + j
                #if re not in li:
                l_re.append(re)
        li = l_re[:]
        count += 1
        if sum_ in li:
            print count
            break
    if min(li) > sum_:
        print -1

宜信

1

少了半小时答题，差一点就搞定了

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s = raw_input()
mo = s.split(' ')
n_mo = map(int, mo)
N, W = n_mo[0], n_mo[1]
if W >= 1:
    li = []
    for i in range(N):
        s_i = str(i)
        li.append(s_i)
    
    itr = li[:]
    for j in range(W-1):
        l_re = []
        
        for k1 in li:
            for k2 in itr:
                if k1 != k2:
                    re = k1 + k2
                    l_re.append(re)
        li = l_re[:]
        
print (W**N - len(li))

新浪面试

一面：

主要招的是视频和图像方向的

  1. 自我介绍
  2. 做的项目
  3. CNN权值
  4. CNN介绍
  5. kmeans GMM 区别
  6. 物体运动快慢
  7. 视频编解码

美团

1

2

10%

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s = raw_input()
s = s.split(' ')
s_n, s_m = s[0], s[1]
c = len(s_n) / 10
c_m = len(s_n) % 10
if c == 0:
    n = int(s_n)
if c > 0:
    su = 0
    for k in range(c):
        for kk in range(-1, -11, -1):
            tem = int(s_n[kk+10*k]) * 10**(-(kk+10*k)-1)
            #print tem
            su = su + tem
    for kk_ in range(-1, -c_m, -1):
        tem = int(s_n[kk_+10*c]) * 10**(-(kk_+10*c)-1)
        su = su + tem
    n = su  
m = int(s_m)
#print n, m
l = [str(x) for x in range(1,n+1)]
ll = ''.join(l)
#print ll
for i in range(m):
    num = raw_input()
    p = ll.find(num)
    ll = num + ll[:p] + ll[p+1:]
    #print ll
    
for j in ll:
    print j

深信服科技校园招聘研发试题–卷B

1

50%

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s = raw_input()
a = s.decode('unicode_escape')
a = a[1:-1]
print a

2

25%

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s = raw_input()
def f(s, set_i_o):
    set_00 = s + set_i_o[0]
    set_01 = set_i_o[1]
    set_10 = set_i_o[0]
    set_11 = set_i_o[1] + s
    return (set_00, set_01), (set_10, set_11)
c = 0
arr = [('','')]# * 2**(c)
while c < len(s):
    l = len(arr)
    for i in range(l):
        a, b = f(s[c], arr[i])
        arr += [a]
        #print arr
        arr += [b]
    arr = arr[2**c:]
    #print arr    
    c += 1
o = [None] * len(arr)    
for i in range(len(arr)):
    o[i] = arr[i][1]+arr[i][0]
s_o = set(o)    
for j in s_o:
    print j
```    
# 人人
## 1
AC
```python
n = int(raw_input())
print (n-1)*n*2 - (n-1)*n + 1

2

50%

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s = raw_input()
arr = map(int, s.split(' '))
n,m,k  = arr[0], arr[1], arr[2]
#print n,m,k
l = []
for i in range(k):
    tem = raw_input()
    arr = map(int, tem.split(' '))
    #print arr
    arr = tuple(arr)
    l.append(arr)
    #print arr,l
a = sorted(l, key=lambda t: t[0])    
b = sorted(l, key=lambda t: t[1])
#print a, b
if a == b:
    p = ''
    if (1,1) not in a:
        a = [(1,1)] + a
    if (n,m) not in a:
        a = a + [(n,m)]
    for i in range(len(a)-1):
        nd = a[i+1][0] - a[i][0]
        nr = a[i+1][1] - a[i][1]
        p += 'D'*nd
        p += 'R'*nr
    print p
else:
    print "Impossible"

3

浪潮

一面

  1. 自我介绍
  2. 突出点
  3. 性格
    明天之前给二面消息，三天内给offer