https://codefights.com/challenge/x9TcPgiFRmgN22W44/main
1000
Nicky and Dev work in a company where each member is given his income in the form of points. On Nicky's birthday, Dev decided to give some of his points as a gift. The number of points Dev is gifting is the total number of visible zeros visible in the string representation of the N points he received this month.
Let's say that Nicky got M points from Dev. By the company law, if M is even and greater than 0, Nicky must give one point to the company. If M is odd, the company gives Nicky one additional point.
Given the number of points N Dev received this month, calculate the number of points Nicky will receive as a gift and return this number in its binary form.
Note: visible zeros are calculated as follows:
0, 6 and 9 contain 1 visible zero each;8 contains 2 visible zeros;- other digits do not contain visible zeros.
Example
For N = "565", the output should be
Cipher_Zeroes(N) = 10.
There's one visible zero in "565". Since one is odd, the company will give an additional point, so Nicky will receive 2 points.
210 = 102, so the output should be 10.
설명문이 길지만 정작 문제에 필요한 조건은 몇 개 없다.
문자열이 주어졌을 때, 그 문자열 내의 특정 조건 (여기서는 0,6,9,8 등의 특정 숫자) 을 찾아내는 것이고
그리고 십진수를 이진수로 변환하는 것.
문제는 매우 쉬우나
중요한건 얼마나 효율적으로 짜는가의 방법.
실제 순위권들을 보면 거의 100 문자 쯤으로 다 완료해낸다. 어떻게 한걸까.
우선 십진법 -> 이진법으로 숫자를 바꾸는 코드
주어진 숫자 dec를 계속해서 2로 나누면서 나머지를 자릿수를 올라가면서 더해가면 된다.