알고리즘 라이브러리 기록용

최대공약수, 최대공배수 - 관련문제 백준 2609

import math
a, b = map(int, input().split())
print(math.gcd(a,b))
print(math.lcm(a,b))

 

입력속도 빠르게

import sys
n = int(sys.stdin.readline())

 

combinations, permutations, product, combinations_with_replacement

from itertools import combinations, permutations
n, m = map(int, input().split())
arr = list(map(int, input().split()))

max_sum = 0
for c in combinations(arr, 3):
    sum_c = sum(c)
    if sum_c <= m:
        max_sum = max(max_sum, sum_c)
print(max_sum)

###
product(arr, repeat=2)

combinations_with_replacement(arr, 2)

 

개수세기

from collections import Counter
l = [1, 2, 3]
cd = Counter(l)

 

팩토리얼

from math import factorial

n, k = map(int, input().split())
result = (factorial(n) // factorial(n-k)) // factorial(k)
print(result)

 

올림, 내림, 반올림

ceil()
floor()
round()

round() = floor(num+0.5)