public static void main(String[] args) throws IOException {
int a=25;
int b=6;
int x=-a%-b;
int y=a%-b;
int z=-a%b;
int r=a%b;
System.out.println(x);//-1
System.out.println(y);//1
System.out.println(z);//-1
System.out.println(r);//1
}
总结:余数的符号与被除数a的符号相同