uva 202 Repeating Decimals

传送门：https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=138

#include<stdio.h>
#include<iostream>
using namespace std;
int s[3003], num[3003], a[3003];  //s是用来存放商的每一位    num是用来存放余数出现的顺序  
                                    // a是用来表示余数i有没有出现过 

/*
 n除以m的余数只能是0~m-1，根据抽屉原则，当计算m+1次时至少存在一个余数相同，
即为循环节；存储余数和除数，输出即可。
*/
int main()
{ 
    //freopen("1.txt" , "r" , stdin);
    int n, m, i, j, k, t, x, y, cycle;
    bool flag ;
    while(~scanf("%d%d", &n, &m)) 
    {
        x = n;
        y = m;
        flag = false;
        memset(s, 0, sizeof(s));
        memset(num, 0, sizeof(num));
        memset(a, 0, sizeof(a));
        t = n/m;
        n = n%m;
        cycle = 0;
        for (i = 0; i <= m; i++)
        {
            a[n] = 1;
            num[i] = n;
            if (!n)
            {
                flag = true;
                break;
            }
            n *= 10;
            s[i] = n/m;
            n %= m;
            if (a[n])
            {
                break;
            }
        }
        printf("%d/%d = %d.", x, y, t);
        for (j = 0; j <= i; j++)
        {
            if(num[j] == n)
            {
                cycle = i - j +1;
                break;
            }
        } 
        if (flag)
        {
            for (j = 0; j < i; j++)
            {
                printf("%d", s[j]);
            }
            printf("(0)\n   1");
        }
        else
        {
            if (cycle >= 50)
            {
                for (k = 0; k < j; k++)
                {
                    printf("%d", s[k]);
                }
                printf("(");
                for(; k < j+50; k++)
                {
                    printf("%d", s[k]);
                }
                printf("...)\n");
            }
            else
            {
                for (k = 0; k < j; k++)
                {
                    printf("%d", s[k]);
                }
                printf("(");
                for(; k <= i; k++)
                {
                    printf("%d", s[k]);
                }
                printf(")\n");
            }
            printf("   %d", cycle);
        }
        printf(" = number of digits in repeating cycle\n\n");
    }
    return 0;
}