练习2-1 编写一个程序以确定分别由signed及unsigned限定的char、short、int、与long类型变量的取值范围

#include <stdio.h>main(){    printf("signed char -1 = %d\n",~0);     /* 0000 0000 - 1111 1111 -1*/    printf("signed char -1 = %d\n",(~0)>>1);    /* 1111 1111 - 1111 1111 -1*/    printf("unsigned char max = %d\n",((unsigned char)~0));    /* 1111 1111 - 1111 1111 255*/    printf("signed char max = %d\n",((unsigned char)~0)>>1);    /* 1111 1111 - 0111 1111 127 右移补0*/    printf("unsigned char max = %d\n",(unsigned char)(~0>>1));    /* 1111 1111 - 1111 1111 255 右移补1*/    printf("unsigned char 254 = %d\n",(unsigned char)(-3>>1));    /* 1111 1101 - 1111 1110 254*/}