定义并调用函数day of year,计算一个日期是该年的第几天答:include<stdio.h>int main(void){ int day1,day=0,month,year,result=0;//day初始化为0int day_of_year(int year,int month,int day);printf("Enter year:");scanf("%d",&year);//去掉\nprintf("Enter month:");scanf("%d",&month);//去掉\nprintf("Enter day:");scanf("%d",...