java - 欧拉计划 8

Question

我已经阅读了有关欧拉问题 8 项目的一些主题。但是我不知道为什么我的代码给出了错误的答案。

package main;

import java.util.ArrayList;

public class Euler8 {

public static void main(String[] args) {
    String bigNumber = "73167176531330624919225119674426574742355349194934"
            + "96983520312774506326239578318016984801869478851843"
            + "85861560789112949495459501737958331952853208805511"
            + "12540698747158523863050715693290963295227443043557"
            + "66896648950445244523161731856403098711121722383113"
            + "62229893423380308135336276614282806444486645238749"
            + "30358907296290491560440772390713810515859307960866"
            + "70172427121883998797908792274921901699720888093776"
            + "65727333001053367881220235421809751254540594752243"
            + "52584907711670556013604839586446706324415722155397"
            + "53697817977846174064955149290862569321978468622482"
            + "83972241375657056057490261407972968652414535100474"
            + "82166370484403199890008895243450658541227588666881"
            + "16427171479924442928230863465674813919123162824586"
            + "17866458359124566529476545682848912883142607690042"
            + "24219022671055626321111109370544217506941658960408"
            + "07198403850962455444362981230987879927244284909188"
            + "84580156166097919133875499200524063689912560717606"
            + "05886116467109405077541002256983155200055935729725"
            + "71636269561882670428252483600823257530420752963450"
            ;
    ArrayList<Integer> myArray = new ArrayList<Integer>();
    int counter = 1;
    int current = 0;
    int product = 1;
    int maximumProduct = 0;
    for(int i = 0; i < bigNumber.length(); i++)  {
        String b = "" + bigNumber.charAt(i);
        current = Integer.parseInt(b);
        myArray.add(current);
        if(counter % 5 == 0) {

            for(int x : myArray) {
                product = x * product;
            }
            if(product > maximumProduct) {
                maximumProduct = product;
            }
            myArray.clear();
            product = 1;
        }
        counter++;
    }
    System.out.println(maximumProduct);
    }
}

我得到的答案是 31752，正确的答案是 40824。由于这是一项家庭作业，我无法复制问题的解决方案，因此我想要任何关于为什么我的代码无法工作的解释，以便我可以修复它。

谢谢。

Answer 1

您没有考虑相乘的正确元素。每个乘积都是通过乘以 5 个连续数字获得的，对于每个数字，下面的代码将这些数字保存在 myArray

public static void main(String[] args) {            
   String bigNumber = "73167176531330624919225119674426574742355349194934"
                + "96983520312774506326239578318016984801869478851843"
                + "85861560789112949495459501737958331952853208805511"
                + "12540698747158523863050715693290963295227443043557"
                + "66896648950445244523161731856403098711121722383113"
                + "62229893423380308135336276614282806444486645238749"
                + "30358907296290491560440772390713810515859307960866"
                + "70172427121883998797908792274921901699720888093776"
                + "65727333001053367881220235421809751254540594752243"
                + "52584907711670556013604839586446706324415722155397"
                + "53697817977846174064955149290862569321978468622482"
                + "83972241375657056057490261407972968652414535100474"
                + "82166370484403199890008895243450658541227588666881"
                + "16427171479924442928230863465674813919123162824586"
                + "17866458359124566529476545682848912883142607690042"
                + "24219022671055626321111109370544217506941658960408"
                + "07198403850962455444362981230987879927244284909188"
                + "84580156166097919133875499200524063689912560717606"
                + "05886116467109405077541002256983155200055935729725"
                + "71636269561882670428252483600823257530420752963450"
                ;

                ;
        ArrayList<Integer> myArray = new ArrayList<Integer>();
        int counter = 1;
        int current = 0;
        int product = 1;
        int maximumProduct = 0;
        for(int i = 0; i < bigNumber.length(); i++)  {
            String b = "" + bigNumber.charAt(i);
            current = Integer.parseInt(b);
            myArray.add(current);
            counter++;
            if(counter == 5) {
                for(int x : myArray) {
                    product = x * product;
                }
                if(product > maximumProduct) {
                    maximumProduct = product;

                }
               myArray.remove(0);
               product = 1;
            }
            counter=myArray.size();
        }
        System.out.println(maximumProduct);
        }
}

另请参阅 Greatest product of five consecutive digits in a 1000-digit number