import java.util.List; import java.util.ArrayList; import java.util.Collections; class Test03 { /** * 产生[min, max)范围的随机整数 */ public static int randomInt(int min, int max) { return (int) (Math.random() * (max - min) + min); } public static void main(String[] args) { List redBalls = new ArrayList<>(); for (int i = 1; i <= 33; ++i) { redBalls.add(i); } List selectedBalls = new ArrayList<>(); for (int i = 0; i < 6; ++i) { selectedBalls.add(redBalls.remove(randomInt(0, redBalls.size()))); } Collections.sort(selectedBalls); selectedBalls.add(randomInt(1, 17)); for (int i = 0; i < selectedBalls.size(); ++i) { System.out.printf("%02d ", selectedBalls.get(i)); if (i == selectedBalls.size() - 2) { System.out.print("| "); } } System.out.println(); } }