怎样用c语言程序对所输入的日期知道它的星期几数答:char str[7][10]={"星期天","星期一","星期二","星期三","星期四","星期五","星期六"};int year,month,day;int IsLeapYear(){ if((year%4==0&&year%100!=0)||(year%400==0))return 1;else return 0;} int month_day(int m){ int mon_day[]={31,28,31,30,31,30,31,...