Codeforces Round #237 (Div. 2) B. Marathon（卡long long）

题目：http://codeforces.com/contest/404/problem/B

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

 int main()
 {
     __int64 g;   //g一定要是长整形，因为数据会超int.这个也是错误的最主要原因
     int n, i;
     double a, d, x, y, sum, cnt;
     while(~scanf("%lf%lf%d", &a, &d, &n))
     {
         sum = (double)(a*);
         for(i = ; i <= n; i++)
         {
             cnt = (double)i*d;

             g =(long long)(cnt/sum); //这里一定把要转换的部分加上括号
             cnt = (double)(cnt-g*sum);
             if(cnt-a<=)
             {
                 y = ;
                 x = cnt;
             }
             else if(cnt-*a<=)
             {
                 x = a;
                 y = cnt-a;
             }
             else if(cnt-*a<=)
             {
                 x = a-(cnt-*a);
                 y = a;
             }
             else
             {
                 x = ;
                 y = a-(cnt-*a);
             }
             printf("%.10lf %.10lf\n", x, y);
         }
     }
     return ;
 }