ceil(x)函数详解

ceil(8.1)=9.0;
ceil(-8.8)=-8.0;

double ceil(double x);

#include <iostream>  
#include<cmath>  
using namespace std;  
int main()  
{  
  float x=9.2;  
  std::cout << "Initial value of x is :"<<x;  
  cout<<'\n';  
  cout<<"final value of x is :"<<ceil(x);  
  return 0;  
}  

#include <iostream>  
#include<cmath>  
using namespace std;  
int main()  
{  
  float x=-2.2;  
  std::cout << "Initial value of x is :"<<x;  
  cout<<'\n';  
  cout<<"final value of x is :"<<ceil(x);  
  return 0;  
}