Modified version of Molly's pro26.c

pro26_molly.c

#include<stdio.h>
#include<sys/types.h>
#include<memory.h>

int findmax(int a[])
{
    int i;
    for(i=1; i<1000; i++)
    {
        if(a[i]>a[0])
            a[0] = a[i];
    }

    return a[0];
}

int find_index(int yu,int yushu[])
{
    int i = 0;
    int pos = -1;

    for(i=0; i<999; i++)
    {
        if(yu == yushu[i])
        {
            pos = i;
            break;
        }
    }
    return pos;
}

void add(int yu,int yushu[])
{
    int i;
    for(i=0; i<999; i++)
    {
        if(yushu[i] == 0)
        {
            yushu[i] = yu;
            break;
        }

    }
}

int div(int a, int d, int yushu[])
{
    int yu = a % d;
    int pos = find_index(yu, yushu);

    add(yu, yushu);

    if (pos != -1)
    {
        return 1;
    }
    else
    {
        return 1 + div(yu*10, d, yushu);
    }
}

int num_of_cycles(int d, int yushu[])
{
    int pos;
    int ret;

    memset(yushu,0,sizeof(int)*1000);
    if(d<10){
        pos = div(10, d, yushu) - 1;
        ret = pos - find_index(yushu[pos], yushu);
    }
    else if(d<100){
        pos = div(100, d, yushu) - 1;
        ret = pos - find_index(yushu[pos],yushu);
    }
    else if(d<1000){
        pos = div(1000, d, yushu) - 1;
        ret = pos - find_index(yushu[pos], yushu);
    }

    return ret;
}

int main()
{
    int pos;
    int rec;
    int i,d;

    int num[1000];
    int yushu[1000];

    memset(yushu,0,sizeof(int)*1000);
    memset(num,0,sizeof(int)*1000);

    for(d=2;d<1000;d++)
    {
        int tmp = d;
        while (tmp%2 == 0) //将num中的因子2全部去除
            tmp /=2;

        while (tmp % 5 == 0) //将num中的因子5全部去除
            tmp /= 5;

        if(tmp==1||tmp==0)
            continue;

        num[d] = num_of_cycles(d, yushu);
    }

    //max length
    rec = findmax(num);

    for(i=1;i<1000;i++)
    {
        if(num[i]==rec)
        {
            d=i;
            break;
        }
    }

    printf("The result is %d\n",d);
    return 0;
}