编写一个带自定义函数的c语言程序,完成输入a.b.c三个值,计算并输出3者...答:///代码如下/// include <stdio.h> int sum(int add_a, int add_b, int add_c){ return (add_a + add_b + add_c);} int main(){ int a, b, c;scanf("%d %d %d", &a, &b, &c);printf("a + b + c = %d \n", sum(a, b ,c));} /// 附件中有///...