int y = -2;

int z;

unsigned int yu = (unsigned int) y;

yu = ~yu;

yu += 1;

z = (int) yu;

printf("%d ", z);

char y = -2;

char z;

unsigned char yu = (unsigned char ) y;

yu = yu & ~(1<<7);

z = (char) yu;

printf("%x ", z);

can you explaine line by line what the above codes mean. Thank you!