...求输入一个年份year,求该年的三月一日是星期几?答:程序1 int sum(int year,int month,int day) /* 算出某日在该年中是第几天*/ { int day_sum=0,i;int day_tab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};for(i=1;i<month;i++)day_sum+=day_tab[i];day_sum+=day;if((year%4==0&&year%100!=0) || (year%...