c语言编程:编写程序,输入某年某月某日,判断这一天是这一年的第几天...答:include <stdio.h> include<Windows.h> void main(){ int y,m,d,sum1=0,sum2=0,i=0,sumok1=0,sumok2=0;int a1[]={31,29,31,30,31,30,31,31,30,31,30,31};int a2[]={31,28,31,30,31,30,31,31,30,31,30,31};printf("输入年月日(用逗号隔开):\n");scanf("%d,%d...