[轉載]計算任何一天是星期幾的C語言源代碼.

#include

int main()

{

int day,mn,yr,i,days=0,s,k;

int mont[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

char wek[][9]={ {'S','u','n','d','a','y'},

{'M','o','n','d','a','y'},

{'T','u','e','s','d','a','y'},

{'W','e','d','n','s','d','a','y'},

{'T','h','u','r','s','d','a','y'},

{'F','r','i','d','a','y'},

{'S','a','t','u','r','d','a','y'}

};

printf("Inpute the date (year-month-day):");

scanf("%d-%d-%d",&yr,&mn,&day);

if (yr%4==0||yr%100==0||yr%400==0)

mont[2]=29;

else

mont[2]=28;

for (i=0;i

days+=mont[i];

days+=day;

s=yr-1+(int)((yr-1)/4)-(int)((yr-1)/100)+(int)((yr-1)/400)+days;

k=s%7;

printf("%d-%d-%d is %s.",yr,mn,day,wek[k]);

return 0;

}

經過測試可以準確計算出輸入的任何日期為星期幾.

清多多指教.