我是Java的新手,我想生成一个长度为'number'的随机(x,y)坐标数组,它不包含重复项。可以重复x或y值,但必须没有重复的(x,y)坐标。输出不必是Points,只是某种方式来保持坐标的x,y值。
我可以生成一个随机点数组,并尝试使用Set来确保没有重复值,但遇到了问题。我尝试使用条件“while(set.size)”和应该禁止重复的'add'方法,以创建包含唯一点的正确大小的输出。
这是代码:
Set<Point> set = new HashSet<Point>();
Random position = new Random();
Point test=new Point();
do{
test.x=position.nextInt(xx);
test.y=position.nextInt(yy);
//xx and yy are the random number limits called from another part of the code
set.add(test);
}
while (set.size()<number);
List<Object> list = new ArrayList<Object>(set);
Object[] coord = list.toArray();
这会输出一个正确长度的数组,但每个元素都是相同的。有人可以提供任何帮助吗?
谢谢
每次循环时,测试指向空间中的相同变量,以修复在循环内创建新实例 - 不仅仅是在它之前一次:
Set<Point> set = new HashSet<Point>();
Random position = new Random();
Point test;
do{
test = new Point();
test.x=position.nextInt(xx);
test.y=position.nextInt(yy);
//xx and yy are the random number limits called from another part of the code
set.add(test);
}
while (set.size()<number);
List<Object> list = new ArrayList<Object>(set);
Object[] coord = list.toArray();
您正在修改相同的点对象。但是,由于每次都更改X和Y,因此您还要更改哈希码和点的相等性,这样您最终会在集合中多次放置相同的对象。有趣的案例。
尝试
do{
test = new Point();
test.x=position.nextInt(xx);
test.y=position.nextInt(yy);
//xx and yy are the random number limits called from another part of the code
set.add(test);
}
while (set.size()<number);
值随机选择但不重复
Random rndm = new Random();
String[] selectedNumber = new String[15];
String[] sequanceNumber = {"1","2","3","4","5","6","7","8","9","10","11","12","13","14","15"};
//*****FIRST LOOP START*****//
for(byte a = 0; a < 15;){
int temp = rndm.nextInt(15)+1;
//*****SECOND LOOP START*****//
for(byte b = 0; b < 15; b++){
String s4 = temp+"";
//*****CHECKING CONDITION START*****//
if(s4.equals(sequanceNumber[b]) ){
selectedNumber[a] = s4;
String s1 = sequanceNumber[b];
s1 = s1.replace(s1, " ");
sequanceNumber[b] = s1;
a++;
}
//*****CHECKING CONDITION END*****//
}
//*****SECOND LOOP END*****//
}
//*****FIRST LOOP END*****//
//*****PRINT ALL RANDOM VALUES BUT NOT REPEATED VALUES*****//
System.out.println(Arrays.toString(selectedNumber));