Question

为什么这个程序会error C2181: 没有匹配 if 的非法 else

# include
# include
int main(void) { int a = 1; int b = 2; int c = 3; float delta; float x1; float x2; delta = b*b - 4a*c; } { if (deta > o) { x1 = (-b + sqrt(delta)) / 2*a; x2 = (-b - sqrt(delta)) / 2*a; printf("一元二次方程的解是 %f\n, %f\n",x1,x2); } else if (delta == 0); { x1 = x2; x2 = (-b ) / 2*a; printf("一元二次方程的解是 %f\n",x1); } else { printf("无解",); } return 0 }
# include <stdio.h>
# include <math.h>
int main(void)
{

int a = 1;
int b = 2;
int c = 3;
float delta;
float x1;
float x2;
delta = b*b - 4a*c;
}
{
if (deta > o)
{
x1 = (-b + sqrt(delta)) / 2*a;
x2 = (-b - sqrt(delta)) / 2*a;
printf("一元二次方程的解是 %f\n, %f\n",x1,x2);

}
else if (delta == 0);
{
x1 = x2;
x2 = (-b ) / 2*a;
printf("一元二次方程的解是 %f\n",x1);

}
else
{
printf("无解",);

}

return 0
}

Answer 1

int main(void)
{
int a = 1;
int b = 2;
int c = 3;
float delta;
float x1;
float x2;
delta = b*b - 4a*c;

if (deta > o)
{
x1 = (-b + sqrt(delta)) / 2*a;
x2 = (-b - sqrt(delta)) / 2*a;
printf("一元二次方程的解是 %f\n, %f\n",x1,x2);
return 0;
}
if (delta == 0)
{
x1 = x2;
x2 = (-b ) / 2*a;
printf("一元二次方程的解是 %f\n",x1);
return 0;
}
if(deta<0)
{
printf("无解",);
}
return 0;
}