UVa 202

每次记录被除数 , 当出现相同被除数时即出现一个完整循环节

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

const int maxn = 1000;
char s[maxn];
char cyc[maxn];
int mo[100000];

int main()
{
    int a,b;
    while( ~scanf("%d%d",&a,&b) )
    {
        memset(s,0,sizeof(s));
        memset(cyc,0,sizeof(cyc));
        memset(mo,0,sizeof(mo));
        if( a == b ){
                printf("%d/%d = 1.(0)
",a,b);
                printf("   1 = number of digits in repeating cycle

");
                continue;
        }
        else
        {
            int z = a / b;
            /*  如果 a能整除b  */
            if( a % b == 0 ){
                printf("%d/%d = %d.(0)
",a,b,z);
                printf("   1 = number of digits in repeating cycle

");
                continue;
            }
            /*  如果 不整除  */
            int cot = a % b;  //每次的余数
            cot *= 10;
            mo[cot] = 1;
            int i = 0;
            int gg = 0; //记录突然整除
            int f = 0;
            while(1){
                while( cot < b ){
                    cot *= 10;
                    s[i] = '0';
                    i++;
                    if(mo[cot]){  f = 1;   break;}
                    mo[cot] = 1;
                }
                if(f) break;
                if( cot % b == 0 )  //突然整除
                {
                    s[i] = cot/b + '0';
                    printf("%d/%d = %d.%s(0)
",a,b,z,s);
                    printf("   1 = number of digits in repeating cycle

");
                    gg = 1;
                    break;
                }
                s[i] = cot/b + '0';
                i++;
                //printf("%d %s
",i,s);
                cot %= b;
                cot *= 10;
                if( mo[cot] ) { break;}
                //printf("%d is marked
",cot);
                mo[cot] = 1;
            }
            //printf("%s
",s);
            if(gg)  continue;
            int cott = a % b;  //第二次循环寻找循环节开始的位置
            cott *= 10;
            int flag = 1;
            int j = 0;
            if( cot == cott )   flag = 0;
            while(flag){
                while( cott < b ){
                    cott *= 10;
                    j++;
                }
                if( cot == cott ) break;
                cott -= cott/b * b;
                cott *= 10;
                if( cott > b && cott == cot ) { j++;  break;}
                if( cott > b )  j++;
            }
            if( i == j ){
                char dd = s[i-1];
                s[j-1] = '';
                printf("%d/%d = %d.%s(%c)
",a,b,z,s,dd);
                printf("   1 = number of digits in repeating cycle

");
                continue;
            }
            int k;
            //printf("i = %d, j = %d %s
",i,j,s);
            int kk = 0;
            int point = 0;
            for( k = j; k < i; k++ ){
                cyc[kk] = s[k];
                kk++;
                if(k == 49){
                    point = 1;
                    break;
                }
            }
            cyc[kk] = '';
            s[j] = '';
            printf("%d/%d = %d.%s(%s",a,b,z,s,cyc);
            if( point ) puts("...)");
            else    puts(")");
            printf("   %d = number of digits in repeating cycle

",i-j);
        }
    }
    return 0;
}