Question

In the following code segment what will be:

• the result of function
• value of x
• value of y

    {
         unsigned int x=-1;
         int y;
         y = ~0;
         if(x == y)
             printf("same");
         else
             printf("not same");
     }

a. same, MAXINT, -1
b. not same, MAXINT, -MAXINT
c. same , MAXUINT, -1
d. same, MAXUINT, MAXUINT
e. not same, MAXINT, MAXUINT

Can someone explain me how its works or can just explain the snippet??

I know it’s about two’s complement n etc..
What is the significance of MAXINT and -1 ?
It is because of unsigned int and int thing – am I right ?

Answer 1

If you run this program, you will see that the answer a is wrong and c is the correct answer:

#include <stdio.h>
#include <limits.h>

int main() {
    unsigned int x=-1;
    int y;
    y = ~0;
    if(x == y)
        printf("same\n");
        if(x==INT_MAX) printf("INT_MAX\n");
        if(x==UINT_MAX) printf("UINT_MAX\n");
    else
        printf("not same");
    return 0;
}