编写C语言程序：黑色星期五

#include <stdio.h>

int normalMonth[12] = {31,28,31,30,31,30,31,31,30,31,30,31}

int leapMonth[12] = {31,29,31,30,31,30,31,31,30,31,30,31}

int getYear(void)

{

int n

printf("please input year:")

scanf("%d",&n)

return n

}

int isLeap(int n)

{

if((n%4==0&&n%100!=0)||n%400==0)

{

return 366

}

else

{

return 365

}

}

int weekDays(int year)

{

int i,sum = 0

for(i = 2008i<yeari++)

{

sum += isLeap(i)

}

if(sum == 0)

{

sum = 0

}

else

{

sum = sum%7

}

switch (sum)

{

case 0:

return 3

break

case 1:

return 4

break

case 2:

return 5

break

case 3:

return 6

break

case 4:

return 7

break

case 5:

return 1

break

case 6:

return 2

break

default:

return -10000

}

}

void darkFriday(int weekday,int year)

{

int week = weekday,i,j,sum = 0

if(366==isLeap(year))

{

for(i=0i<12i++)

{

for(j=1j<=leapMonth[i]j++)

{

week++

if(week == 8)

{

week = 1

}

if(week == 5&&j == 13)

{

sum ++

}

}

}

}

else

{

for(i=0i<12i++)

{

for(j=1j<=normalMonth[i]j++)

{

week++

if(week == 8)

{

week = 1

}

if(week == 5&&j == 13)

{

sum ++

}

}

}

}

printf("%d\n",sum)

}

int main(void)

{

int year,weekday

year = getYear()

weekday = weekDays(year)

darkFriday(weekday,year)

return 0

}

可能不对，你看看吧。楼上的可能更好。

main()

{

int i//红球

int j//白球

int k//黑球

int count=0

for(i=0i<=3i++)

for(j=1j<=5j++)//必有白球

for(k=0k<=6k++)

if(i+j+k==8)

{

printf("%d\t%d\t%d",i,j,k)

count++

}

printf("%d",count)

}

---