用C语言函数输入某年某月某日，判断这一天是这一年的第几天？

#include<stdio.h>
int allday(int year)
{
int day=365;
if(year%4==0&&year%100!=0||year%400==0)
day=366;
return day;
}
int a(int month)
{
if(month<=12&&month>=1);
switch(month)
{
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
case 9:
case 10:
case 11:
case 12:
return month;
}
}
main()
{
int year,month,day,sum;
printf("输入一个年份");
scanf("%d",&year);
printf("今年一共有%d天\n",allday(year));
printf("输入一个月份");
scanf("%d",&month);
printf("这是今年的第%d月\n",a(month));
printf("输入要查询的那天");
scanf("%d",&day);
// printf("这天是今年的%d天",h(day));

}

这是我没做完的,我不会怎么计算这一天是一年中的第几天呀!~

你的函数h（day）只传入一个参数，怎么计算天数呢？改成3个参数就可以直接返回了int h（int year;int month,int day）
{
     int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
     int s=0,i;
     for(i=0;i<month;i++)
          s=s+a[i];
          if((year%4==0&&year%100!=0||year%400==0)&&month>2)
           return s+day+1;
           else
           return s+day;
}

你的函数h（day）只传入一个参数，怎么计算天数呢？改成3个参数就可以直接返回了int h（int year;int month,int day） { int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}; int s=0,i; for(i=0;i<month;i++) s=s+a[i]; if((year%4==0&&year%100!=0||year%400==0)&&month>2) return s+day+1; else return s+day; }

好深奥啊！

short finddays(short year, short month, short day) { short toReturn = day; switch (month) { case 12:toReturn += 30; case 11:toReturn += 31; case 10:toReturn += 30; case 9:toReturn += 31; case 8:toReturn += 31; case 7:toReturn += 30; case 6:toReturn += 31; case 5:toReturn += 30; case 4:toReturn += 31; case 3:toReturn += (year % 4 ? 28 : 29); case 2:toReturn += 31;break; default:break; } return toReturn; }

|#include <stdio.h> #include <stdlib.h> static int daytable[2][13] = { {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} }; void get_day ( int year, int *dayofyear, int month, int day ) { int i, leap; leap = (( year % 4 == 0 ) && ( year % 100 != 0 ) || ( year % 400 == 0 )); *dayofyear = 0; for (i=1;i< month;i++) { *dayofyear = *dayofyear + daytable[leap][i]; } *dayofyear = *dayofyear + day; } void main() { int year,month,day; int days; printf("Enter the year month day (for example: 2008 3 1)\n"); scanf("%d %d %d",&year,&month,&day); (void) get_day ( year, &days, month, day ); printf("the days=%d\n",days); }