Signed and unsigned integers

signed_unsigned.c

#include <stdio.h>

int main(int argc, char* argv[])
{
    union
    {
        signed short int signed_short_int;
        unsigned short int unsigned_short_int;
        struct {unsigned char char1; unsigned char char2;} s;
    } u;

    signed short int a;
    unsigned short int b;

    a = -1;
    b = (unsigned short int)a;

    u.signed_short_int = a;

    puts("binary arrangement:");

    printf("sshort\t= %d\n",   u.signed_short_int);
    printf("ushort\t= %d\n",   u.unsigned_short_int);
    printf("byte 0\t= %d\n", u.s.char1);
    printf("byte 1\t= %d\n", u.s.char2);

    printf("a\t= %d\n", a);
    printf("b\t= %d\n", b);

    int i;

    puts("signed overflow:");

    a = 32765;
    for (i=0; i<5; i++)
    {
        printf("++a\t= %d\n", ++a);
    }

    puts("unsigned overflow:");

    b = 65533;
    for (i=0; i<5; i++)
    {
        printf("++b\t= %d\n", ++b);
    }

    return 0;
}