对应程序：
#include<reg52.h>
#define uint unsigned int
#define uchar unsigned char
uchar code tab[]={
0x81,
0x42,
0x24,
0x18,
};
void delay(uint z)
{
uint i,j;
for(i=z;i>0;i--)
for(j=120;j>0;j--);
}
void init()
{
P0=0x00;
}
