因此,我查看了“可能已经有了答案的问题”,但是,尽管收到与这些问题相同的错误消息,但我认为我可能有一个不同的问题:

//find greatest product generated by 5 consecutive integers below

class project_euler8 {

    public static String numbers =
    "73167176531330624919225119674426574742355349194934" +
    "96983520312774506326239578318016984801869478851843" +
    "85861560789112949495459501737958331952853208805511" +
    "12540698747158523863050715693290963295227443043557" +
    "66896648950445244523161731856403098711121722383113" +
    "62229893423380308135336276614282806444486645238749" +
    "30358907296290491560440772390713810515859307960866" +
    "70172427121883998797908792274921901699720888093776" +
    "65727333001053367881220235421809751254540594752243" +
    "52584907711670556013604839586446706324415722155397" +
    "53697817977846174064955149290862569321978468622482" +
    "83972241375657056057490261407972968652414535100474" +
    "82166370484403199890008895243450658541227588666881" +
    "16427171479924442928230863465674813919123162824586" +
    "17866458359124566529476545682848912883142607690042" +
    "24219022671055626321111109370544217506941658960408" +
    "07198403850962455444362981230987879927244284909188" +
    "84580156166097919133875499200524063689912560717606" +
    "05886116467109405077541002256983155200055935729725" +
    "71636269561882670428252483600823257530420752963450";

    public static int calculateProduct(int[] myArray) {
        int product = 1;
        for (int i = 0; i < myArray.length; i++) {
            product *= myArray[i];
        }
        return product;
    }

    public static void main(String[] args) {
        //declare biggest_product, temporary array
        int biggest_product = 0;
        int[] temp = new int[5];
        //loop through each sequence of 5 integers
            for (int i = 0; i < numbers.length() - 5; i++) {
                int remainder = i % 5;
                **temp[remainder] = Integer.parseInt(numbers[i]);**
                int candidate_product = calculateProduct(temp);
                if (candidate_product > biggest_product) {
                    biggest_product = candidate_product;
                }
            }
        System.out.println("Biggest product is " + biggest_product);
    }


编译器不喜欢的行在上面加粗了。如果我在for循环中声明数组(temp),是否可以解决此问题?我有点困惑为什么我不能基于数组索引按元素分配整数值...

我知道Java中的数组是不可变的,但是如果是这种情况,在数组声明后的任何时候如何分配值?

最佳答案

numbers未声明为数组;而是一个String

如果要遍历String中的每个字符,则可以通过numbers.charAt(i)完成。

但是,由于返回的是一个char而不是String,因此必须对其进行适当的转换(即,从数字字符中减去'0'以对其进行归一化)。

由于char确实是int(范围较短),因此Integer中没有方便的方法将char转换为int,因此必须减去char 找回电话号码。

该解决方案如下所示:

temp[remainder] = numbers.charAt(i) - '0';


这意味着您需要做更多工作来更改接受'0'的方法的签名,但我将其留给读者练习。

08-08 00:34
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