报数问题

public static void fun(int n ,int m){ 
List<Integer> arr = new ArrayList<Integer>() ;
for(int i=1 ;i<=n ;i++){
arr.add(i) ;
}
int targetPeopleIndex = 0 ;
while(arr.size() > 1){
targetPeopleIndex = targetPeopleIndex + m - 1 ;
targetPeopleIndex = targetPeopleIndex % arr.size() ;
System.out.println("targetPeopleIndex = " + arr.get(targetPeopleIndex)) ;
arr.remove(targetPeopleIndex) ;
}
System.out.println("targetPeopleIndex = " + arr.get(0)) ;
}