c - 欧拉 #8 的解决方案

Question

#include <stdio.h>

int main(void)
{
    char *num = "73167176531330624919225119674426574742355349194934"
    "96983520312774506326239578318016984801869478851843"
    "85861560789112949495459501737958331952853208805511"
    "12540698747158523863050715693290963295227443043557"
    "66896648950445244523161731856403098711121722383113"
    "62229893423380308135336276614282806444486645238749"
    "30358907296290491560440772390713810515859307960866"
    "70172427121883998797908792274921901699720888093776"
    "65727333001053367881220235421809751254540594752243"
    "52584907711670556013604839586446706324415722155397"
    "53697817977846174064955149290862569321978468622482"
    "83972241375657056057490261407972968652414535100474"
    "82166370484403199890008895243450658541227588666881"
    "16427171479924442928230863465674813919123162824586"
    "17866458359124566529476545682848912883142607690042"
    "24219022671055626321111109370544217506941658960408"
    "07198403850962455444362981230987879927244284909188"
    "84580156166097919133875499200524063689912560717606"
    "05886116467109405077541002256983155200055935729725"
    "71636269561882670428252483600823257530420752963450";


int i, tmp=1, product = 0;


for(i = 0; num[i] != NULL; i++)
{

    tmp *= (num[i] - '0');

    if((i+1) % 5 == 0)
    {

        if(tmp > product)
            product = tmp;

        tmp = 1;
    }

}

printf("Largest product ------> %i\n", product);

return 0;
}

对象是求出这个1000位数字中五个连续数字的最大乘积。答案是 40824，但我的解决方案生成 31752。关于我哪里出错的任何想法？

Answer 1

您只能找到第 5 组 5 个连续数字中的最高乘积，而不是所有 5 个连续数字中的最高乘积。您只查看了 20% 的可能组合。

例如在第一行数据上，您看到的第一个序列是“96983”。第二个是“52031”。

您错过了“69835”、“98352”、“83520”和“35203”。