local variable 'b' used without having been initialized
 local variable 'a' used without having been initialzed
 warning C4700: local variable 'c' used without having been initialized
我的程序一直是输出“无解”
# include <stdio.h>
# include <math.h>
int main(void)
{
    double a,b,c;
    double x1,x2;
    double delta;
   
    printf("请输入三个数值\n");
    delta = b * b - 4 * a * c ;
    printf("a = ");
    scanf("%lf",&a);
    printf("b = ");
    scanf("%lf",&b);
    printf("c = ");
    scanf("%lf",&c);
    do
    {
    if(delta > 0)
    {
        x1 = (-b+sqrt(delta))/(2*a);
        x2 = (-b-sqrt(delta))/(2*a);
        printf("x1= %lf,x2 = %lf\n",x1,x2);

    }
    if(delta == 0)
    {
        x1 = (-b)/(2*a);
        x2 = x1;
        printf("x1 = x2 =%lf\n");


    }
    else if(delta < 0)
    {

        printf("无解\n");

    }
    }while(1);


    return 0;
}