如果你是说CS1102 lab 0的话import java.io.*; import java.util.*; import java.text.NumberFormat; class Q4 { //main class public static void main(String []args) throws Exception{ BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in)); String thisLine; StringTokenizer st; double a, b; boolean blank = false; NumberFormat nf = NumberFormat.getInstance(); nf.setMaximumFractionDigits(2); nf.setMinimumFractionDigits(2); while((thisLine=stdin.readLine())!=null){ st = new StringTokenizer(thisLine); a = Double.parseDouble(st.nextToken()); b = Double.parseDouble(st.nextToken()); if (blank) System.out.print(" "); else blank = true; System.out.print(nf.format(a/b)); } System.out.println(); } }