Standard Template Library (STL) Interview Questions And Answers

#include<stdio.h>
#include<iostream.h>

int main()
{
char* mystrstr(char*,char*);
char str1[20];
char str2[10];
cout<<"\n Enter two strings\t";
cin>>str1>>str2;
cout<<"\nstr1 = "<<str1<<" str2 "<<str2 ;
char* c= mystrstr(str1,str2);
if(c!=NULL)
printf("\nc = %s\n",c);
return 0;
}

char* mystrstr(char* str1, char* str2)
{
char *cp = (char *) str1;
char *s1, *s2;

if ( !*str2 )
return((char *)str1);
while (*cp)
{
s1 = cp;
s2 = (char *) str2;
while ( *s1 && *s2 && !(*s1-*s2) )
{
s1++;
s2++;
}

if (!*s2)
{
printf("\n string found\n");
return(cp);
}
cp++;
}
return(NULL);
}

Readers-Writers Problem:
The readers-writers problem is a classic synchronization
problem in which two
distinct classes of threads exist, reader and writer.
Multiple reader threads
can be present in the Database simultaneously. However, the
writer threads must
have exclusive access. That is, no other writer thread, nor
any reader thread,
may be present in the Database while a given writer thread
is present. Note:
the reader/writer thread must call startRead()/startWrite()
to enter the
Database and it must call endRead()/endWrite() to exit the
Database.
class Database extends Object {
private int numReaders = 0;
private int numWriters = 0;
private ConditionVariable OKtoRead = new ConditionVariable
();
private ConditionVariable OKtoWrite = new ConditionVariable
();
public synchronized void startRead() {
while (numWriters > 0)
wait(OKtoRead);
numReaders++;
}
public synchronized void endRead() {
numReaders--;
notify(OKtoWrite);
}
public synchronized void startWrite() {
while (numReaders > 0 || numWriters > 0)
wait(OKtoWrite);
numWriters++;
}
public synchronized void endWrite() {
numWriters--;
notify(OKtoWrite);
notifyAll(OKtoRead);
}
}
class Reader extends Object implements Runnable {
private Monitor m = null;
public Reader(Monitor m) {
this.m = m;
new Thread(this).start();
}
public void run() {
//do something;
m.startRead();
//do some reading…
m.endRead();
// do something else for a long time;
}
}
class Writer extends Object implements Runnable {
private Monitor m = null;
public Writer(Monitor m) {
this.m = m;
new Thread(this).start();
}
public void run() {
//do something;
m.startWrite();
//do some writing…
m.endWrite();
// do something else for a long time;
}
}
- 2 -
wait(ConditionVariable cond) {
put the calling thread on the “wait set” of cond;
release lock;
Thread.currentThread.suspend();
acquire lock;
}
notify(ConditionVariable cond){
choose t from wait set of cond;
t.resume();
}
notifyAll(ConditionVariable cond){
forall t in wait set of cond;
t.resume()
}
For the following scenarios, we assume that only one reader
thread and one writer
thread are running on the processor.

explain some of your real time examples

Method overloading is to overload methods using same class
name by writing different parameters.This is called Method
Overloading.

linked list means node which is connected each other with
a line. it means that each node is connected with another
one. Each node of the list hold the referance of the next
node.
if we talk about the sorted linked list , it is also a list
just like another list. but the differce is only that it
hold all the nodes in a sequantial manner either in
accending order decending order

common operater meachine a particular user technical
education research

OR

C - Conventional
O - Organization of
M - Man
P - Power
U - Utilitilised
T - Tachnical
E - Enhancement
R - Resource.

c++ is object oriented programming language.. the main
function value should return.

#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
int i,j,sum;
printf("enter two numbers");
scanf("%d%d",&i,&j);
sum=i+j;
printf("sum=%d",sum);
}

In linux fork() system call is used to create a child
process. The Child process inherits some properties of its
parent and operates in a separate memory space

#include<iostream.h>
#include<conio.h>
class person
{
int person;
float salery;
}p;
cout<<"enter the person name";
cin>>p.person;
cout<<"enter the salery";
cin>>p.salery;
}
void main()
{
person;
getch();
}

27 4 is the output.

the call to the macro sets a = b*b*b with b = 3, 3 cubed is 27
then b is incremented to 4 after the macro call

To avoid local copy of object reference (&) is used in copy
constructor.
Moreover if the & is ommited then copy constructor goes in
infinite loop.
eg. if class name is Sample.

Copy constructor without &
Sample :: Sample (Sample s)
{
//Code goes here
}

and we create object as follows. ;
Sample s;
Sample s1(s);

In this scenario program will go in infinite loop.

it is a device

#include<iostream.h>
#include<conio.h>

class BOX
{
private:
int l,b,h;
public:
void input();
void print();
long volume(long,int,int);
};
void BOX::input()
{
cout<<"input values of l,b,&h"<<"\n";
cin>>l>>b>>h;
}
void BOX::print()
{
cout<<"volume="<<"\n";
}
void BOX::volume()
{
long volume(long l,int b,int h);
{
return(l*b*h);
}
}
void main()
{
set BOX b1;
b1.input();
b1.print();
b1.volume();
return;
}

Thread is a smallest unit of process. In process have one
or more thread.

VC++ uses all C++ features. VC++ has GUI and it is user
friendly.It has many programming features
likeWin32, MFC, ATL, ActiveX, DLL's etc.