Question

嘿伙计们我试图获得生日相同的人数，但这个解决方案没有用。这个程序显示0.0％。请帮助我......！。

public double calculate(int size, int count) {
    int matches = 0;//initializing an integer variable
    boolean out = false;
    List<Integer> days=new ArrayList<Integer>();// creating arraylist name days  of type int
    for (int j = 0; j <count; j++) {
        for (int i = 0; i < size; i++) {// initializing for loop till less than size
            Random rand = new Random(); // creating an object of random function

            int Brday = rand.nextInt(364) + 0;//initializing the limit of randomc number chozen

            days.add(Brday); //adding values to arraylist
        }

        for (int l = 0; l < size; l++) {
            int temp = l;//assigning value of l to a variable
            for (int k = l + 1; k < size; k++) {
                if (days.get(k) == temp) {// check statement to check values are same

                    matches++;//incrementing variable
                    out = true;
                    mOut.print("Count does have same birthday" + matches);
                    break;

                } else {
                    mOut.print("does not have same birthday");

                }
            }
            if (out) {
                out = false;
                break;
            }

        }
    }
    double prob = (double) matches / count;
    mOut.print("The probability for two students to share a birthday is " + prob*100 + ".");
    return prob;//returning double value of the function
}

Answer 1

实际上，您的代码获得0％或100％。如果您想查看，请尝试使用calculate(100, 100)调用它。

此代码中有两个错误。首先，如果您多次运行模拟（count> 1），那么您永远不会在第二次迭代之前清除生日列表。

您的方法应该以：

开头

public double calculate(int size, int count) {
    int matches = 0;
    boolean out = false;
    List<Integer> days;
    for (int j = 0; j <count; j++) {
        days = new ArrayList<Integer>();

其次，您不是比较两个生日，而是将生日与列表中的索引进行比较。

这一行：

int temp = l;//assigning value of l to a variable

应阅读：

int temp = days.get(l); // Remember the birthday at index l

通过这些更改，您将获得更好的结果。

通过结构数据查找类似的生日

1 个答案: