Repeating Decimals
UVA - 202
题目传送门
解决方法：模拟一下除法，及时记录余数，当一个余数第二次出现时证明开始循环
AC代码
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <map>
#include <stack>
#include <queue>
#include <vector>
#include <bitset>
#include <set>
#include <utility>
#include <sstream>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define inf 0x3f3f3f3f
#define rep(i,l,r) for(int i=l;i<=r;i++)
#define lep(i,l,r) for(int i=l;i>=r;i--)
#define ms(arr) memset(arr,0,sizeof(arr))
//priority_queue<int,vector<int> ,greater<int> >q;
const int maxn = (int)1e5 + 5;
const ll mod = 1e9+7;
int yushu[maxn];
int shang[maxn];
int wei[maxn];
int main()
{#ifndef ONLINE_JUDGEfreopen("in.txt", "r", stdin);#endif//freopen("out.txt", "w", stdout);ios::sync_with_stdio(0),cin.tie(0);int n,m;int cnt=0;while(scanf("%d %d",&n,&m)!=EOF){int k=n;ms(yushu);ms(shang);ms(wei);int count=0;shang[count++]=n/m;n=n%m;while(!wei[n]&&n){wei[n]=count;yushu[count]=n;shang[count++]=n*10/m;n=n*10%m;}printf("%d/%d = %d.",k,m,shang[0]);int i;for(i=1;i<count&&i<=50;i++){if(yushu[i]==n&&n)printf("(");printf("%d",shang[i]);}if(n==0)printf("(0");if(count>50)printf("...");printf(")\n");printf(" %d = number of digits in repeating cycle\n\n",!n?1:count-wei[n]);}return 0;
}
)
