这些错误是什么意思?怎么改才能运行
#include <reg52.h>
sbit bw= P3^0;
sbit sw= P3^1;
sbit gw= P3^2;
unsigned ZXM[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
void main()
{
int k=456;
while(1)
{
P0=ZXM[k/100+1];
bw=1;
sw=gw=0;
delay(500);
P0=ZXM[(k/10)%10+1];
sw=1;
gw=bw=1;
delay(500);
P0=ZXM[k%10+1];
gw=0;
bw=sw=1;
delay(500);
}
}