C language exercise 59: In-depth understanding of the value range of the char type

In-depth understanding of the value range of the char type

For example: 

#include <stdio.h>
int main()
{
 char a[1000];
 int i;
 for(i=0; i<1000; i++)
 {
  a[i] = -1-i;
 }
 printf("%d",strlen(a));
 return 0;
}

 The result is 255

 a+b prints the result in the form of %d: 300

Since the value range of unsigned char is limited in c, in the above figure, turning 55 times clockwise from 255 can get 44