C语言结构体多函数传参及递归程序调试 &符号前语法错误求解

你遇到的error: expected ‘;’, ‘,’ or ‘)’ before ‘&’ token报错属于C/C语法差异类错误：C语言原生不支持引用（&）传参语法，该特性为C独有，使用C编译器编译带C++引用写法的代码就会触发该类报错，你代码中共有3处使用了引用传参的写法，对应你提到的3个同源错误。

• 调整scan_complex、print_complex、multiply_complex三个函数的形参定义：将struct complex &a改为指针形式struct complex *a，函数内部访问结构体成员的.运算符替换为->
• 调整上述三个函数的调用逻辑：传参时传入结构体地址（前缀加&），如果原参数是结构体指针则直接传递不需要解引用

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

struct complex
{
    int real;
    int img;
};


void scan_complex(struct complex *a)
{
    printf("Enter a and b where a + ib is the complex number.");
    
    printf("\na = ");
    scanf("%d", &a->real);
    
    printf("b = ");
    scanf("%d", &a->img);
}


void print_complex(struct complex *a)
{
    printf(" %d + %di", a->real, a->img);
}


struct complex * add_complex(struct complex *a,struct complex *b)
{
    struct complex *c = (struct complex *)malloc(sizeof(struct complex));
    
    c->real = a->real + b->real;
    c->img = a->img + b->img;

    return c;
}


void multiply_complex(struct complex *a, struct complex *b)
{
    struct complex c;
    
    c.real = a->real*b->real - a->img*b->img;
    c.img = a->img*b->real + a->real*b->img;

    if (c.img >= 0)
    {
        printf("Multiplication of the complex numbers = %d + %di", c.real, c.img);
    }
    else
    {
        printf("Multiplication of the complex numbers = %d %di", c.real, c.img);
    }
}

struct complex* f(int n, struct complex *c)
{
    if(n==0)
        return c;
    return add_complex(c,f(n-1,c));
}


float abs_complex(struct complex c)
{
    return sqrt(c.real*c.real + c.img *c.img);
}

int main()
{
    struct complex a;
    struct complex b;

    scan_complex(&a);
    scan_complex(&b);

    printf("absolute of : ");
    print_complex(&a);
    printf(" %f\n",abs_complex(a));
    printf("\n");

    print_complex(&a);
    printf(" + ");
    print_complex(&b);
    printf(" = ");
    struct complex *c =add_complex(&a,&b);
    print_complex(c);
    printf("\n");

    multiply_complex(&a,&b);
    printf("\n");

    struct complex *d = f(3,&a);
    print_complex(d);
    printf("\n");

    // 补充：可自行添加free释放malloc申请的内存避免泄漏
    free(c);
    // 注意f函数递归申请的多层内存需要额外逻辑释放，此处仅做示例
    return 0;
}

如果你不想修改为指针传参，也可以将代码后缀改为.cpp使用C++编译器编译，也可以解决当前报错。

内容的提问来源于stack exchange，提问作者Mike