문제
A jail has a number of prisoners and a number of treats to pass out to them. Their jailer decides the fairest way to divide the treats is to seat the prisoners around a circular table in sequentially numbered chairs. A chair number will be drawn from a hat. Beginning with the prisoner in that chair, one candy will be handed to each prisoner sequentially around the table until all have been distributed.
The jailer is playing a little joke, though. The last piece of candy looks like all the others, but it tastes awful. Determine the chair number occupied by the prisoner who will receive that candy.
- Example
n = 4
m = 6
s = 2
There are 4 prisoners,6 pieces of candy and distribution starts at chair 2 .
The prisoners arrange themselves in seats numbered 1 to 4.
Prisoners receive candy at positions 2,3,4,1,2,3 .
The prisoner to be warned sits in chair number 3 .
예시
INPUT 1
2
5 2 1
5 2 2
OUTPUT 1
2
3
INPUT 2
2
7 19 2
3 7 3
OUTPUT 2
6
3
풀이
- 죄수가
n명, 캔디가m개, 첫 캔디를 먹는s번 죄수가 있을 때, 마지막 캔디를 먹는 죄수번호를 구하는 문제이다. - 캔디 개수를 사람 수만큼 나누고 남은 나머지만큼 s를 더하면, 마지막 캔디를 먹는 죄수의 번호를 구할 수 있다.
코드
function saveThePrisoner(n, m, s) {
let last = s + (m % n) - 1;
if (last > n) last -= n;
else if (last === 0) last = n;
return (last);
}