Tutorials

Tell how to check whether a linked list is circular.

Create two pointers, each set to the start of the list. Update each as follows:

while (pointer1) {
pointer1 = pointer1->next;
pointer2 = pointer2->next; if (pointer2) pointer2=pointer2->next;
if (pointer1 == pointer2) {
print (\”circular\n\”);
}
}

OK, why does this work?

If a list is circular, at some point pointer2 will wrap around and be either at the item just before pointer1, or the item before that. Either way, it’s either 1 or 2 jumps until they meet.

How can you quickly find the number of elements stored in a a) static array b) dynamic array ?

Why is it difficult to store linked list in an array?

How can you find the nodes with repetetive data in a linked list?

Write a progamme to accept a given string in any order and flash error if any of the character is different. For example : If abc is the input then abc, bca, cba, cab bac are acceptable but aac or bcd are unacceptable.

This is a C question that I had for an intern position at Microsoft: Write out a function that prints out all the permutations of a string. For example, abc would give you abc, acb, bac, bca, cab, cba. You can assume that all the characters will be unique. After I wrote out my function, he asked me to figure out from the code how many times the printf statement is run, and also questions on optimizing my algorithm.

What’s the output of the following program? Why?

#include
main()
{
typedef union
{
int a;
char b[10];
float c;
}
Union;

Union x,y = {100};
x.a = 50;
strcpy(x.b,\”hello\”);
x.c = 21.50;

printf(\”Union x : %d %s %f \n\”,x.a,x.b,x.c );
printf(\”Union y :%d %s%f \n\”,y.a,y.b,y.c);
}

Given inputs X, Y, Z and operations and & (meaning bitwise OR and AND, respectively)

What is output equal to in

output = (X & Y) (X & Z) (Y & Z)

Explain which of the following declarations will compile and what will be constant - a pointer or the value pointed at:
const char *
char const *
char * const
Note: Ask the candidate whether the first declaration is pointing to a string or a single character. Both explanations are correct, but if he says that it’s a single character pointer, ask why a whole string is initialized as char* in C++. If he says this is a string declaration, ask him to declare a pointer to a single character. Competent candidates should not have problems pointing out why const char* can be both a character and a string declaration, incompetent ones will come up with invalid reasons.

You’re given a simple code for the class BankCustomer. Write the following functions:
Copy constructor
= operator overload
== operator overload
+ operator overload (customers’ balances should be added up, as an example of joint account between husband and wife)
Note:Anyone confusing assignment and equality operators should be dismissed from the interview. The applicant might make a mistake of passing by value, not by reference. The candidate might also want to return a pointer, not a new object, from the addition operator. Slightly hint that you’d like the value to be changed outside the function, too, in the first case. Ask him whether the statement customer3 = customer1 + customer2 would work in the second case.

What problems might the following macro bring to the application?

#define sq(x) x*x

Consider the following struct declarations:

struct A { A(){ cout << \"A\"; } }; struct B { B(){ cout << \"B\"; } }; struct C { C(){ cout << \"C\"; } }; struct D { D(){ cout << \"D\"; } }; struct E : D { E(){ cout << \"E\"; } }; struct F : A, B { C c; D d; E e; F() : B(), A(),d(),c(),e() { cout << \"F\"; } }; What constructors will be called when an instance of F is initialized? Produce the program output when this happens. Anything wrong with this code? T *p = new T[10]; delete p; Note: Incorrect replies: “No, everything is correct”, “Only the first element of the array will be deleted”, “The entire array will be deleted, but only the first element destructor will be called”. Anything wrong with this code? T *p = 0; delete p; Note: Typical wrong answer: Yes, the program will crash in an attempt to delete a null pointer. The candidate does not understand pointers. A very smart candidate will ask whether delete is overloaded for the class T. Explain virtual inheritance. Draw the diagram explaining the initialization of the base class when virtual inheritance is used. Note: Typical mistake for applicant is to draw an inheritance diagram, where a single base class is inherited with virtual methods. Explain to the candidate that this is not virtual inheritance. Ask them for the classic definition of virtual inheritance. Such question might be too complex for a beginning or even intermediate developer, but any applicant with advanced C++ experience should be somewhat familiar with the concept, even though he’ll probably say he’d avoid using it in a real project. Moreover, even the experienced developers, who know about virtual inheritance, cannot coherently explain the initialization process. If you find a candidate that knows both the concept and the initialization process well, he’s hired. What’s potentially wrong with the following code? long value; //some stuff value &= 0xFFFF; Note: Hint to the candidate about the base platform they’re developing for. If the person still doesn’t find anything wrong with the code, they are not experienced with C++. What does the following code do and why would anyone write something like that? void send (int *to, int * from, int count) { int n = (count + 7) / 8; switch ( count % { case 0: do { *to++ = *from++; case 7: *to++ = *from++; case 6: *to++ = *from++; case 5: *to++ = *from++; case 4: *to++ = *from++; case 3: *to++ = *from++; case 2: *to++ = *from++; case 1: *to++ = *from++; } while ( –n > 0 );
}
}

In the H file you see the following declaration:

class Foo {
void Bar( void ) const ;
};

Tell me all you know about the Bar() function

Write a short code using C++ to print out all odd number from 1 to 100 using a for loop

for( unsigned int i = 1; i < = 100; i++ ) if( i & 0×00000001 ) cout << max="4;" total ="0;" average="0;">>numb;
if((numb <5)&&(numb>9))
cout<<”please re type your input”;
else
for(i=0;i<=MAX; i++)
{
total = total + numb;
average= total /MAX;
}

return 0;
}

Can you be bale to identify between Straight- through and Cross- over cable wiring? and in what case do you use Straight- through and Cross-over?

Straight-through is type of wiring that is one to to one connection Cross- over is type of wiring which those wires are got switched. We use Straight-through cable when we connect between NIC Adapter and Hub. Using Cross-over cable when connect between two NIC Adapters or sometime between two hubs.

If you hear the CPU fan is running and the monitor power is still on, but you did not see any thing show up in the monitor screen. What would you do to find out what is going wrong?

I would use the ping command to check whether the machine is still alive(connect to the network) or it is dead.