Baekjoon 1193번(python)

a = int(input())
i = 0
while a >0:
    a -= i
    i += 1
    
a = i+a-1
res = str(a)+'/'+str(i-a)
if i %2 == 0:
    res = str(i-a)+'/'+str(a)

print(res)

 

(무식하게 짠 코드, 시간초과, 0.7~0.9초정도)

k = int(input())

a = 1
b = 1
ab_flags = True

if(k == 1):
    print('1/1')

for _ in range(k - 1):
    if(ab_flags):
        if(a == 1):
             ab_flags = False
        else:
            a -= 1
        b += 1
    else:
        if(b == 1):
            ab_flags = True
        else:
            b -= 1
        a += 1

print('{}/{}'.format(a, b))