5-9.c

一些简单的c51程序

#include <stdio.h>
#include <reg51.h> 
void main( )
{
int year, month,day,i,leap=0;
	     static int day_tab[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 } };
     
	  SCON = 0x50; 
TMOD |= 0x20; 
TH1 = 0xf3; 
TR1 = 1;
TI = 1; 
	 
	 printf("/n");
     scanf("%d%d%d",&year,&month,&day);
	     leap = year % 4 == 0 && year % 100 != 0 || year % 400 ==0;
     for ( i=0;i<month;++i)
	       day+=day_tab[leap][i];
	     printf("%d\n",day);
}