java - Java 中的 for 循环 - 指数

Question

基本上，有20只羊为一组。当羊群发展到80只羊后，就不再需要有人看管了。每年 t 的羊数量 N 可以通过以下公式找到:

N = 220/(1 + 10(0.83)^t)

该程序试图找出羊需要被监管多少年，并写出 t 的 N 值，从 0 开始，一直到 25。

这是我到目前为止的代码...它似乎不起作用，我知道与乘以幂的部分有关。我尝试使用变量“power”，在循环的每次迭代中乘以 0.83。感谢任何帮助，谢谢。

   public static void main(String[] args) {

    System.out.println("A breeding group of 20 bighorn sheep is released in a protected area in Colorado.");
    System.out.println("After the group has reached a size of 80 sheep, the group does not need to be supervised anymore.");
    System.out.println("This program calculates how many years the sheep have to be supervised.");
    int number = 20;
    int power = 1;
    for(int years = 0; number < 80; power*= 0.83) {
        number = 220 / (1 + 10 * power);           
        System.out.println("After " + years + " years, the number of sheep is: " + number);
        years++;
    }
}
 }

Answer 1

将数字和幂的数据类型从 int 更改为 double。我尝试了一下，运行正确。您可能还需要修改 for 循环，使其在 Years < 25 时运行，而不是 number < 80。并让 number 成为循环内的局部变量以保持整洁。

public static void main(String[] args) {
    System.out.println("A breeding group of 20 bighorn sheep is released in a protected area in Colorado.");
    System.out.println("After the group has reached a size of 80 sheep, the group does not need to be supervised anymore.");
    System.out.println("This program calculates how many years the sheep have to be supervised.");
    double power = 1;
    boolean foundFirstOverEighty = false;
    for (int years = 0; years < 25; years++) {
        double number = 220 / (1 + 10 * power);
        System.out.println("After " + years + " years, the number of sheep is: " + number);

        if (!foundFirstOverEighty && number >= 80) {
            System.out.println("First time number of sheep exceeded eighty. " + years + " years. number of sheep is: " + number);
            foundFirstOverEighty = true;
        }

        power *= 0.83;
    }
}