codeforces 404 B Marathon【fmod对浮点数取余】

 1 #include<iostream>  
 2 #include<cstdio>  
 3 #include<cstring> 
 4 #include <cmath> 
 5 #include<stack>
 6 #include<vector>
 7 #include<map> 
 8 #include<set>
 9 #include<queue> 
10 #include<algorithm>  
11 using namespace std;
12 
13 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
14 
15 typedef long long LL;
16 const int INF = (1<<30)-1;
17 const int mod=1000000007;
18 const int maxn=100005;
19 
20 double a,d;
21 int n;
22 
23 void f(double len){
24     int ans=(int)(len/a)%4;
25     len=fmod(len,a);
26     if(ans==0) printf("%f 0\n",len);
27     if(ans==1) printf("%f %f\n",a,len);
28     if(ans==2) printf("%f %f\n",a-len,a);
29     if(ans==3) printf("0 %f\n",a-len);
30 }
31 
32 
33 int main(){    
34     cin>>a>>d>>n;
35     d = fmod(d, 4 * a);
36     for(int i=1;i<=n;i++) f(i*d);
37 }