[Daily 코테] 백준 11050번: 이항 계수 1

https://www.acmicpc.net/problem/11050

11050번: 이항 계수 1

 

First Try 1

import time
import math
start = time.time()
n, k = map(int, input().split())
result = 1
for i in range(k):
  result *= n-i
result /= math.factorial(k)
print(int(result))
finish = time.time()
print(f'time: {round(finish-start,3)}')

>>> 10

>>> time: 3.205

First Try 2

import time
start = time.time()
n, k = map(int, input().split())
result = 1
for i in range(k):
  result *= n-i
for j in range(1,k+1):
  result /= j
print(int(result))
finish = time.time()
print(f'time: {round(finish-start,3)}')

>>> 10

>>> time: 1.732

 

math.factorial 함수보다 반복문을 사용한 방법이 약 두배정도 빠르다.