程序没报错，但不能运行

#include
#include
#pragma warning(disable:4996)
int main()
{
int a, k;
int b;
printf("请输入a,b的值车型和公里：");
if (a = "夏利" || b <= 3)
{
k = 7;
printf("输出k值");
}
else if (a = "夏利" || b > 3)
{
k = (b - 3) * 5.1 + 7;
printf("输出k值");
}
else if (a = "富康" || b <= 3)
{
k = 8;
printf("输出k值");
}
else if (a = "富康" || b > 3)
{
k = (b - 3) * 5.4 + 8;
printf("输出k值");
}
else if (a = "桑塔纳" || b <= 3)
{
k = 9;
printf("输出k值");
}
else if (a = "桑塔纳" || b > 3)
{
k =(b - 3) * 5.7 + 9;
printf("输出k值");
}
return 0;
}

a == 用 ==判断是否相等

一个=是赋值，两个=号才是判断