(Java)为除法程序生成随机数

Question

嗨，我是编程新手，我正在尝试制作一个可以生成2个随机数的除法程序，条件是第一个数必须大于第二个数，并且它们不给出余数。如果生成的数字不满足条件，它将继续生成，直到满足条件为止。有人能帮我纠正错误吗？

randomnum1 = 1 + (int)(Math.random()*9);
randomnum2 = 1 + (int)(Math.random()*9);
while (randomnum1 < randomnum2 && randomnum1/randomnum2 % 2 != 0) {
randomnum1 = 1 + (int)(Math.random()*9);
randomnum2 = 1 + (int)(Math.random()*9);
int number1 = randomnum1;
int number2 = randomnum2;
int a = number1/number2;

//rest of program is below this

Answer 1

您的while条件检查除法结果是否为偶数randomnum1/randomnum2 % 2 != 0
您应该替换：

while (randomnum1 < randomnum2 && randomnum1/randomnum2 % 2 != 0) {

带

while (randomnum1 < randomnum2 || randomnum1 % randomnum2 != 0) {
// while (!(randomnum1 >= randomnum2 && randomnum1 % randomnum2 == 0)) {
randomnum1 = 1 + (int)(Math.random()*9);
randomnum2 = 1 + (int)(Math.random()*9);
}
// randomnum1 and randomnum2 now match your expectations
int a = number1/number2;

由于rand1 modulo rand2 == 0意味着

他们不给出余数

Answer 2

另一种方法是使用无限循环，并在满足条件时中断循环。

public class Main {
public static void main(String[] args) {
int randomNum1, randomNum2;
while (true) {// An infinite loop
randomNum1 = 1 + (int) (Math.random() * 9);
randomNum2 = 1 + (int) (Math.random() * 9);
if (randomNum1 > randomNum2 && randomNum1 % randomNum2 == 0) {
System.out.println(randomNum1 + " / " + randomNum2 + " = " + (randomNum1 / randomNum2));
break;// Break the loop
}
}
}
}

样本运行：

8 / 2 = 4

Answer 3

public static void main(String[] args) {
int randomnum1=1 + (int)(Math.random()*99);
int randomnum2=1 + (int)(Math.random()*99);

while(randomnum1 % randomnum2 != 0 || randomnum1==randomnum2) {
//prints first numbers generated 
System.out.println(randomnum1+" "+randomnum2);
randomnum1=1 + (int)(Math.random()*99);
randomnum2=1 + (int)(Math.random()*99);

}
if (true) {
//prints  numbers generated that made the statement true
System.out.print("true :"+randomnum1+" "+randomnum2);
}
}


}

Answer 4

一个更好的方法，不必使用任何循环，就是做一些数学技巧，如下所示：

public class SpecialRandom{

public void generate(){
int first = 2 + (int) (Math.random() * 99);
int second = 1 + (int) (Math.random() * 99);
// to guarantee the second is always smaller
if (second>=first){ second%=first; }
if (second==0) { second++; }
first += second - (first%second); //to  correct remainder
System.out.println((first>second && first%second==0)
+ " : " +first+ " ,  " +second);
}

/*TESTING*/
public static void main(String []args){
SpecialRandom sr = new SpecialRandom();
for(int j=0; j<25; j++){ sr.generate(); }
} 
}

结果

true : 28 ,  4
true : 64 ,  32
true : 22 ,  11
true : 18 ,  3
true : 28 ,  14
true : 18 ,  6
true : 92 ,  23
true : 96 ,  6
true : 130 ,  65
true : 28 ,  14
true : 87 ,  29
true : 87 ,  29
true : 74 ,  37
true : 112 ,  56
true : 66 ,  6
true : 10 ,  1
true : 88 ,  44
true : 68 ,  34
true : 156 ,  78
true : 22 ,  11
true : 95 ,  1
true : 86 ,  43
true : 14 ,  1
true : 82 ,  41
true : 98 ,  14