c++ 判斷兩個double是否相等

#include <stdio.h>
#include <iostream>
#include<math.h>
using namespace std;



bool equal(double num1,double num2)

{

if((num1-num2>-0.000001)&&(num1-num2)<0.000001)
    return true;
    else return false;

}

int main()
{
    double  e;
    double f;
    e = 0.05-0.075;
    f= 0.025-0.05;
    if(equal(e,f))
    {
        printf("%f\n%f",e,f);
        printf("=");
    }else
    {
        printf("%f\n%f",e,f);
        printf("!=");
    }
     
  
      
       system("pause");
     
}