C編程:輸入年月日,計算離今天還有幾天

int main(void)

{

int year,month,data,days;

int x=1,y=1,z=1,sum=0,a=0,b,i,j;

int a0[12]={31,28,31,30,31,30,31,31,30,31,30,31};

int a1[12]={31,29,31,30,31,30,31,31,30,31,30,31};

printf("please input the data:\n");

scanf_s("%d%d%d",&year,&month,&data);

if ((year>9999)||(year<1990))

x=0;

if((month>12)||(month<=0))

y=0;

if((year%4==0&&year%100!=0)||year%400==0) //判斷是否為閏年

{

if((data>a1[month-1])||(data<=0))

z=0;

}

else if((data>a0[month-1])||(data<=0))

z=0;

if (x&&y&&z==0)

printf("the data is illegal\n");

else

{

for (i=1990;i<year;i++)

if ((i%4==0&&i%100==0)||i%400==0)

a++;

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

for (j=0;j<month;j++)

sum+=a1[j];

else

for(j=0;j<month;j++)

sum+=a0[j];

days=(year-1990)*365+sum+data+a;

printf("離今天還有%d天\n",days);

return 0;

}