参考代码1021-1026

 1 #include <bits/stdc++.h>           
 2 using namespace std;                
 3 int main()                      
 4 {   
 5     double r,v;
 6     const float PI=3.1415927;
 7     cin>>r;
 8     v=4.0/3*PI*r*r*r;
 9     printf("%.3lf",v);
10     return 0;
11   }

 1 #include <bits/stdc++.h>           
 2 using namespace std;                
 3 int main()                      
 4 {   
 5     int a;
 6     double b;
 7     cin>>a>>b;
 8     a=abs(a);
 9     b=fabs(b);
10     cout<<a<<" "<<b<<endl; 
11     return 0;
12   }

1 #include <bits/stdc++.h>           
2 using namespace std;                
3 int main()                      
4 {   
5     double x;
6     cin>>x;
7     cout<<ceil(x)<<" "<<floor(x)<<endl; 
8     return 0;
9   } 

 1 #include <bits/stdc++.h>           
 2 using namespace std;                
 3 int main()                      
 4 {   
 5     double x,y;
 6     cin>>x;
 7     y=sqrt(x);
 8 //    cout<<fixed<<setprecision(3)<<y<<endl;
 9     printf("%.3lf",y);
10     return 0;
11   } 

1 #include <bits/stdc++.h>           
2 using namespace std;                
3 int main()                      
4 {   
5     int n,a;
6     cin>>n>>a;
7     cout<<pow(n,a)<<endl;
8     return 0;
9   }