用c语言写代码，要求读入4个整数a.b.c.d，根据这4个整数构造两个复数：a+bi和c+di，然后输出它们，并输出它们的和，差，积，商以及上述结果中的最大者(实，虚部运算时均在整数范围内进行运算)

在C语言中，我们可以使用结构体来表示复数，并定义相应的操作函数。以下是实现这个需求的一个示例：

#include <stdio.h>

// 定义复数结构体
typedef struct {
    int real;
    int imag;
} Complex;

// 加法、减法、乘法、除法及比较大小的函数
Complex add(Complex c1, Complex c2);
Complex subtract(Complex c1, Complex c2);
Complex multiply(Complex c1, Complex c2);
Complex divide(Complex c1, Complex c2);
int max_complex(Complex a, Complex b);

int main() {
    int a, b, c, d;
    
    // 读取四个整数
    printf("请输入四个整数a, b, c, d：");
    scanf("%d %d %d %d", &a, &b, &c, &d);

    // 构造复数
    Complex num1 = {a, b};
    Complex num2 = {c, d};

    // 输出复数
    printf("复数a+bi = (%d, %d)\n", num1.real, num1.imag);
    printf("复数c+di = (%d, %d)\n", num2.real, num2.imag);

    // 计算并输出加法、减法、乘法、商
    Complex sum = add(num1, num2);
    Complex diff = subtract(num1, num2);
    Complex prod = multiply(num1, num2);
    Complex quotient = divide(num1, num2); // 注意处理除数为0的情况

    printf("和 = (%d, %d)\n", sum.real, sum.imag);
    printf("差 = (%d, %d)\n", diff.real, diff.imag);
    printf("积 = (%d, %d)\n", prod.real, prod.imag);
    printf("商 (假设非零) = (%d, %d)\n", quotient.real, quotient.imag);

    // 找出较大值
    Complex max = max_complex(sum, diff);
    if (max == sum) {
        printf("实部最大值: %d\n", max.real);
        printf("虚部最大值: %d\n", max.imag);
    } else {
        printf("实部最大值: %d\n", diff.real);
        printf("虚部最大值: %d\n", diff.imag);
    }

    return 0;
}

// 函数定义
Complex add(Complex c1, Complex c2) {
    return (Complex){c1.real + c2.real, c1.imag + c2.imag};
}

Complex subtract(Complex c1, Complex c2) {
    return (Complex){c1.real - c2.real, c1.imag - c2.imag};
}

Complex multiply(Complex c1, Complex c2) {
    int real = c1.real * c2.real - c1.imag * c2.imag;
    int imag = c1.real * c2.imag + c1.imag * c2.real;
    return (Complex){real, imag};
}

// 商函数需要检查除数是否为0，这里仅作简化演示，实际应用中请添加条件判断
Complex divide(Complex c1, Complex c2) {
    return (Complex){c1.real / c2.real, c1.imag / c2.imag};
}

int max_complex(Complex a, Complex b) {
    return a.real > b.real ? a : b;
}

运行此程序，它会提示用户输入四个整数，然后计算并输出相关操作的结果以及最大值。