自学C语言，出现错误不知道怎么办，求大神帮忙
# include <stdio.h># include <math.h>
int main (void)
{
int a = 1;
int b = 2;
int c = 3;
double delta;
double x1;
double x2;
delta = b*b - 4*a*c;
if (delta > 0)
{
x1 = (-b + sqrt(delta)) / (2*a);
x2 = (-b - sqrt(delta)) / (2*a);
printf("该一元二次方程有两个解, x1=%f, x2=%f\n", x1, x2);
}
else if (delta == 0)
{
x1 = (-b) / (2*a);
x2 = x1;
printf("该一元二次方程有唯一解, x1 = x2 = %f\n", x1);
}
else (delta < 0)
{
printf("无解\n");
}
return 0;
}
错误： error C2143: syntax error : missing ';' before '{'
