用C++编写一个程序,判断星期几?答:include "stdio.h"main(){ int day,month,year,sum,leap;printf("\nplease input year,month,day\n");scanf("%d,%d,%d",&year,&month,&day);switch(month)/*先计算某月以前月份的总天数*/ { case 1:sum=0;break;case 2:sum=31;break;case 3:sum=59;break;case 4:sum=90;break;c...