HackerRank Pairs

提出

code: python

import math

import os

import random

import re

import sys

import itertools

#

# Complete the 'pairs' function below.

#

# The function is expected to return an INTEGER.

# The function accepts following parameters:

# 1. INTEGER k

# 2. INTEGER_ARRAY arr

#

def pairs(k, arr):

# Write your code here

arr.sort()

# arr is not sequence

ans = 0

for i in itertools.combinations(arr, 2):

ans += 1

return ans

if __name__ == '__main__':

first_multiple_input = input().rstrip().split()

arr = list(map(int, input().rstrip().split()))

result = pairs(k, arr)

fptr.write(str(result) + '\n')

fptr.close()

解答

code: python

import math

import os

import random

import re

import sys

#

# Complete the 'pairs' function below.

#

# The function is expected to return an INTEGER.

# The function accepts following parameters:

# 1. INTEGER k

# 2. INTEGER_ARRAY arr

def pairs(k, arr):

s = set(arr)

ans = 0

for v in arr:

if v + k in s:

ans += 1

return ans

if __name__ == '__main__':

first_multiple_input = input().rstrip().split()

arr = list(map(int, input().rstrip().split()))

result = pairs(k, arr)

fptr.write(str(result) + '\n')

fptr.close()

提出

code: python

import math

import os

import random

import re

import sys

#

# Complete the 'pairs' function below.

#

# The function is expected to return an INTEGER.

# The function accepts following parameters:

# 1. INTEGER k

# 2. INTEGER_ARRAY arr

#

def pairs(k, arr):

# Write your code here

sarr = set(arr)

ans = 0

for n in arr:

if n - k in sarr:

ans += 1

if n + k in sarr:

ans += 1

return ans // 2

if __name__ == '__main__':

first_multiple_input = input().rstrip().split()

arr = list(map(int, input().rstrip().split()))

result = pairs(k, arr)

fptr.write(str(result) + '\n')

fptr.close()

提出

code: python

import math

import os

import random

import re

import sys

#

# Complete the 'pairs' function below.

#

# The function is expected to return an INTEGER.

# The function accepts following parameters:

# 1. INTEGER k

# 2. INTEGER_ARRAY arr

#

# 1 5 3 4 2 k=2

#

# - Have to avoid O(n)^2

def pairs(k, arr):

s = set(arr)

ans = 0

for v in arr:

if v + k in s:

ans += 1

return ans

if __name__ == '__main__':

first_multiple_input = input().rstrip().split()

arr = list(map(int, input().rstrip().split()))

result = pairs(k, arr)

fptr.write(str(result) + '\n')

fptr.close()