| EVELYN DU

Home > Interview > CS Tutorial > Interview Qs

Questions

Question 1:

在一条单行道上，有n只乌龟向同一个方向爬行。他们的初始速度各不相同，可以假设分别为1(cm/s),2(cm/s).…n(cm/s),(假定vi小于vj,如果i小于j的话)且初始位置完全随机。由于是单行道，当后方的乌龟追上前方乌龟时，它将不得不减速，然后紧跟着前方乌龟爬行，形成一个小组。经过足够长的时间，乌龟们会分成多少组?

1
2
3
4
5
6
7
8
9
10
11
12
13
#i:velocity;location[i]:position
location=[10,3,6,1,8]
location=[(i,location[i]) for i in range(len(location))]
location.sort(key=lambda x: x[1])
group=len(location)

for i in range(len(location)-1):
    j=i+1
    if location[i][0]>location[j][0]:
        group-=1
    i+=1

print(group,location,location[0],location[1])

Knoeledge

1. Normal Function VS类函数

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
def two_sum(nums, target):
    for i in range(len(nums)):
        for j in range(i+1, len(nums)):
            if nums[j] == target - nums[i]:
                return [i, j]

nums = [2, 7, 8, 9]
target = 9
result = two_sum(nums, target)
print(result)  


#类函数
class Solution:
    def two_sum(self, nums, target):
        for i in range(len(nums)):
            for j in range(i+1, len(nums)):
                if nums[j] == target - nums[i]:
                    return [i, j]

# 创建 Solution 类的实例
solution = Solution()

# 调用 two_sum 方法
nums = [2, 7, 8, 9]
target = 9
result = solution.two_sum(nums, target)
print(result)

2.函数内部赋值

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
##报错原因：在函数内部对nums的赋值仅在函数内部有效，并没有原地修改输入的nums数组
class Solution(object):
    def removeElement(self, nums, val):
        blanket=[]
        for i,ch in enumerate(nums):
            if nums[i] != val:
                blanket.append(ch)
        nums=blanket
        return len(blanket),nums

solution = Solution()
val=3
nums = [3,2,2,3]
result = solution.removeElement(nums,val)
print(result)

Data Cleaning and Matrix Processing

1
2
3
4
5
# index place
positions.loc[spread.index[i], 'long'] = capital / prices1[i]
#cumulative multiply
cumulative_returns = x.cumprod()

...
Evelyn Du
2023-09-11
Expand all Back to top Go to bottom