解法一
用一个list模拟删除过程
public static int josephRing(int n, int m) {
if (n < 1 || m < 1) {
return -1;
}
List<Integer> array = new ArrayList<>();
for (int i = 0; i < n; i++) {
array.add(i);
}
int step = 0;
while (array.size() > 1) {
step += m;
step = (step) % array.size() - 1;
if (step < 0) {
array.remove(array.size() - 1);
step = 0;
} else {
array.remove(step);
}
}
return array.get(0);
}
解法二
数学公式，推到过程还没看懂
public static int josephRing2(int n, int m) {
if (n < 1 || m < 1) {
return -1;
}
int last = 0;
for (int i = 2; i <= n; i++) {
last = (last + m) % i;
}
return last;
}
