1 今天继续看了第三章 还写了第三章的题
2 一些关于数组的工具函数
package Array;
import java.util.Arrays;
public class ArraySort {
public static void main(String[] args){
int[] ary = {2,3,4,5,9,7,8};
Arrays.sort(ary); //排序
System.out.println(Arrays.toString(ary)); //打印数组
int index = Arrays.binarySearch(ary, 3); //二分法
System.out.println(index);
}
}
关于产生随机数的函数:
package Array; import java.util.Random; public class RandomDome { public static void main(String[] args){ Random ran = new Random(); int a = ran.nextInt(10000);//随机生成0~10000之间的整数 System.out.println(a); } }
双色球:
package Array; import java.util.Arrays; import java.util.Random; public class DoubleColor { public static void main(String[] args){ String[] pool={"01","02","03","04","05","06","07","08", "09","10","11","12","13","14","15","16","17","18", "19","20","21","22","23","24","25","26","27","28", "29","30","31","32","33"}; boolean[] used = new boolean[pool.length]; String[] balls = new String[6]; Random random = new Random(); int i; int index=0; while(true){ i=random.nextInt(pool.length); if(used[i]){ continue; } balls[index++]=pool[i]; used[i]=true; if(index==balls.length){ break; } } Arrays.sort(balls); String[] newBalls=new String[7]; for(int m=0;m<balls.length;m++){ newBalls[m]=balls[m]; } newBalls[newBalls.length-1]=pool[random.nextInt(16)]; System.out.println("双色球:"+Arrays.toString(newBalls )); } }