#include<stdio.h>

#include<math.h>

 int  main(){

  int a,b,c;

  int x1,x2,x3;

  int answer;

  int x;

  while(scanf("%d%d%d",&a,&b,&c)!=EOF){

  answer=sqrt(b*b-4*a*c);

  if(answer>0){

  x1=(-b+answer)/2a;

  x2=(-b-answer)/2a;

  printf("Two different roots x1=%d,x2=%d,x1,x2);

}

else if(answer==0){

x3=-b/2a;

printf("Two same roots x=%d,x3);

}

else {

printf("No real root");

}

}

 }

  x1=(-b+answer)/2a;

  x2=(-b-answer)/2a;

  x3=-b/2a;

2a應該要改成 (2*a)試試看