题解 | #一元二次方程的计算#

注意德塔==0时，判断x分母的值若等于0，就直接输出0.00 否则输出-0.00

#include <stdlib.h>
#include<stdio.h>
#include<math.h>
int main(){
    	float a=0,b=0,c=0;
    	float x1,x2;
    	while(scanf("%f %f %f",&a,&b,&c)!=EOF){
    	//	float d=b*b-4*a*c;
            if(a==0)
    		printf("Not quadratic equation");
    		 else {
    		 	float d=b*b - 4*a*c;
			if(d==0)
			{
                float s=-b+sqrt(d);
                if(s==0){
                    printf("x1=x2=%.2f\n",s);
                }
                else{
    			printf("x1=x2=%.2f\n",(-b)/2.0/a); 
			}
            }
			 else if(d<0){
				printf("x1=%.2f-%.2fi;x2=%.2f+%.2fi\n",-b/2/a,sqrt(-d)/2/a,-b/2/a,sqrt(-d)/2/a);
			}
             
            else      
			    printf("x1=%.2f;x2=%.2f\n",(-b-sqrt(d))/2.0/a,(-b+sqrt(d))/2.0/a);
	}
}
    return 0;

}