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

int main(){
float a, b, c, d, e, f;
while(cin >>a >>b >>c){
  d = sqrt(b*b-a*4*c);
  e = (-b+d)/2*a;
  f = (-b-d)/2*a;      
  if(d<0)
       cout <<"No real root" <<endl;          
  else if(d>0){
      if(e>f)
       cout << "Two different roots x1=" << e << " , x2=" << f << endl;
      else if(e<f)
       cout << "Two different roots x1=" << f << " , x2=" << e << endl;
  }
  else if(d==0){
       if(b==0)cout << "Two same roots x=" << b/2*a << endl;
       else cout << "Two same roots x=" << -b/2*a << endl;}
}      
return 0;
}

他的No real root一直跑不出來，而且最後一項一直跑出

*** 第 5 點 (20%)：WA
與正確輸出不相符(line:1)
您的答案為: Two same roots x=-4
正確答案為: Two same roots x=-1

請問能告訴我為什麼嗎?

謝謝 > <