功能:类型修饰符long和unsigned的使用
#include<stdio.h>
main()
{
char a1,b1;
unsigned char a2,b2;
int x1,y1;
long x2,y2;
a1=127; b1=129;
a2=127; b2=129;
x1=32767; y1=32769;
x2=32767; y2=32769;
printf("a1=%d,a2=%u,b1=%d,b2=%u\n",a1,a2,b1,b2);
printf("x1=%d,x2=%u,y1=%d,y2=%u\n",x1,x2,y1,y2);
}