Saturday, June 1, 2013

Cheated by Naukri.com

My experience with Naukri.com :

After 6 months in my first job I learned some new skills and I thought I should update them on linkedin or Naukri.com, not because I was looking to change my job just because I fuc***g acquired some new skills.

After a few days of my update my manager calls me to his office and asks me why do I want to change job? I was shocked at first I did not understand why he was saying that. I just assured him that I was very much satisfied with my job and have no reason to look for another,which was 100% truth at that point of time .

Thinking about the incident later it became very clear that the only reason for him to think that I am looking for a change is my naukri profile.

Later when I talked with some of my senior colleagues things became crystal clear. HR of my company takes employee attrition very seriously and they have premium consultant accounts at all major job search websites and continuously monitor employee activities.

This can happen to you too, so do not post anything on these fu****g sites unless you are very sure of leaving the company.

Anyways these site are pretty much useless and only shows useless job openings.

Saturday, May 18, 2013

Quick sort c++ code

Bucket sort C++ code

For in-depth understanding of Data Structure and Algorithm concepts refer :

1) INTRODUCTION TO ALGORITHMS by Coremen Introduction to Algorithms, 3rd Edition From flipkart.com
Introduction to Algorithms, 3rd Edition From amazon.com
Introduction to Algorithms from amazon.in

2) DATA STRUCTURES USING C AND C++ by Tenenbaum M Aaron - DATA STRUCTURES USING C AND C++ by Tenenbaum M Aaron from flipkart.com
Data Structures Using C and C++ (2nd Edition) from amazon.com
Data Structures Using C and C++ from amazon.in

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

class node
{
    public:
        float info;
        node *next,*prev;
        node(){next=prev=0;}
        node(int n, node *ptr=0, node *ptr1=0)
        {
            info=n;
            next=ptr;
            prev=ptr1;
        }
};

/* sort the link list of elements*/
void isort(node *head)
{
    if (head == 0)
        return;
    float key;
    node *j,*i, *q=0;

    for(i=head->next;i!=0;i=i->next)
    {
        q=0;
        key = i->info;
        j=i->prev;
        while(j!=0 && key < (j->info) )
        {
            j->next->info=j->info;
            q = j;
            j=j->prev;
        }

        if(q!=0)
            q->info = key;
    }

}

void bucket_sort(float *a,int n)
{
    /* create buckets */
    node* *b = new node* [n];
    for(int i=0; i<n;i++)
        b[i]=0;

    /* step 2 begins - insert a[i] into buckets */
    for(int i=0;i<n;i++)
    {
        int index=n*a[i];

        node *temp=new node(sizeof(node));
        temp->info=a[i];

        if(b[index]==NULL)
        {
            b[index]=temp;
        }
        else
        {
            temp->next=b[index];
            b[index]->prev=temp;
            b[index]=temp;
        }
    } // end of for
    /* step 2 ends */

    /* step 3 begins - sort each bucket */
    for(int i=0; i<n;i++)
    {
        isort(b[i]);
    }
    /* step 3 ends */

    /* step 4 begins - concatenate all the buckets */
    node *trav=0;
    cout<<"\n\nSorted array is: \n";
    for(int i=0; i<n;i++)
    {
        trav = b[i];
        while(trav != 0)
        {
            cout<<trav->info<<" ";
            trav = trav->next;
        }
    }
    /* step 4 ends */
}

void main()
{
    clrscr();

    int n;
    float *a;

    cout<<"\n\t Enter the size of array : ";
    cin>>n;

    cout<<"\n\t Enter the elements of an array :\n";
    a=new float[n];
    for(int l=0;l<n;l++)
        cin>>a[l];

    cout<<"\n\t Unsorted array is..\n";
    for(l=0;l<n;l++)
        cout<<a[l]<<" ";
    cout<<"\n" ;

    /* sort lements using buckt sort */
    bucket_sort(a,n);

    getch();
}

Radix sort c++ code

priority queue c++ code

For in-depth understanding of Data Structure and Algorithm concepts refer :

1) INTRODUCTION TO ALGORITHMS by Coremen Introduction to Algorithms, 3rd Edition From flipkart.com
Introduction to Algorithms, 3rd Edition From amazon.com
Introduction to Algorithms from amazon.in

2) DATA STRUCTURES USING C AND C++ by Tenenbaum M Aaron - DATA STRUCTURES USING C AND C++ by Tenenbaum M Aaron from flipkart.com
Data Structures Using C and C++ (2nd Edition) from amazon.com
Data Structures Using C and C++ from amazon.in

#include<iostream.h>
#include<conio.h>
#include<process.h>
int n;
void maxheapinsert(int [],int key);
void heapincreasekey(int a[],int i,int key);
int heapextractmax(int a[]);
int prioritymaximum(int a[]);
void max_heapify(int a[20],int n1);
int heapsize;
int left(int i)
{
    return(2*i);
}
int right(int i)
{
    return((2*i)+1);
}
void max_heapify(int A[20],int i)
{
    int l,r,largest,s;
    l=left(i);
    r=right(i);

    if(l<=heapsize && A[l]>A[i])
        largest=l;
    else
        largest=i;

    if(r<=heapsize && A[r]>A[largest])
        largest=r;

    if(largest!=i)
    {
        s=A[i];
        A[i]=A[largest];
        A[largest]=s;
        max_heapify(A,largest);
    }
}
int prioritymaximum(int a[])
{

    return a[1];
}
int heapextractmax(int a[])
{
    if(n<0)
        cout<<"Underflow"<<endl;
    int max=a[1];
    a[1]=a[n];
    n--;
    max_heapify(a,1);
    return max;
}

void heapincreasekey(int a[],int i,int k)
{
    if(k<a[i])
        cout<<"New key is smaller than current key"<<endl;
    a[i]=k;
    while(i>1&&a[i/2]<a[i])
    {
        int t=a[i];
        a[i]=a[i/2];
        a[i/2]=t;
        i=i/2;
    }
}
void maxheapinsert(int a[],int k)
{
    n=n+1;
    a[n]=-999;
    heapincreasekey(a,n,k);
}

void main()
{
    int x,i2,c,key,a[20];
    a[0]=-999;
    int m;
    for( ; ; )
    {
        cout<<"Menu:"<<endl;
        cout<<"1:To get the maximum value"<<endl;
        cout<<"2:To extract maximum value"<<endl;
        cout<<"3:To increase key value"<<endl;
        cout<<"4:To insert new value"<<endl;
        cout<<"5:Exit:"<<endl;
        cout<<"Enter your choice"<<endl;
        cin>>c;
        switch(c)
        {
            case 1:
                x=prioritymaximum(a);
                cout<<x<<endl;
                break;
            case 2:
                m=heapextractmax(a);cout<<"process with priority "<<m<<" is being processed";
                break;
            case 3:
                cout<<"Enter the index value that is to modified "<<endl;
                cin>>i2;
                cout<<"Enter the new value"<<endl;
                cin>>key;
                heapincreasekey(a,i2,key);
                cout<<"Value modified"<<endl;
                break;
            case 4:
                cout<<"Enter the new value"<<endl;
                cin>>key;
                maxheapinsert(a,key);
                break;
            case 5:
                exit(0);
            default:
                cout<<"Wrong code"<<endl;
        }
    }
    getch();
}

Merge sort C++ code

Insertion sort C++ code

Tuesday, May 14, 2013

Time/Space complexity of sorting algorithms

Sorting

Algorithm	Data Structure	Time Complexity			Worst Case Auxiliary Space Complexity
		Best	Average	Worst	Worst
Quicksort	Array	`O(n log(n))`	`O(n log(n))`	`O(n^2)`	`O(log(n))`
Mergesort	Array	`O(n log(n))`	`O(n log(n))`	`O(n log(n))`	`O(n)`
Heapsort	Array	`O(n log(n))`	`O(n log(n))`	`O(n log(n))`	`O(1)`
Bubble Sort	Array	`O(n)`	`O(n^2)`	`O(n^2)`	`O(1)`
Insertion Sort	Array	`O(n)`	`O(n^2)`	`O(n^2)`	`O(1)`
Select Sort	Array	`O(n^2)`	`O(n^2)`	`O(n^2)`	`O(1)`
Bucket Sort	Array	`O(n+k)`	`O(n+k)`	`O(n^2)`	`O(nk)`
Radix Sort	Array	`O(nk)`	`O(nk)`	`O(nk)`	`O(n+k)`

Six Interesting Facebook Tricks That You Might Not Know

Almost everyone of us have now been using Facebook since years, but there are a lot of things that we still are unaware of. Here are 6 interesting tricks that you might not know about Facebook.

1.Trick to update blank status:

Simply enter @[3:3: ] in your status update box. To update your blank status as a long statement, paste the code one below another as showed below:
@[3:3: ]
@[3:3: ]
@[3:3: ]

2. Download Full Facebook Album in a single click:

Now you can download a full Facebook album in a single click. Just visit this app called Facebook2zip. Facebook2zip.com

3. Go offline for a particular person:

Instead of going offline for all of your friends, now you can go OFFLINE for a particular person. Just open that person's chat pane and click on the settings button. You'll find a button saying 'Turn off chat for xyz', just click and you are done.

4. Facebook status update from Desired Device (via iPhone without an iPhone):

Login to your Facebook account and update your status, just visit and search for your desired device on top right corner of the page: http://statusvia.org/apps/Facebook/

5. Update Facebook status with symbols:

Facebook status symbols do not have to use the inbuilt facility. But we're cool with the status message through the use of symbols is a Facebook trick. Just visit: http://fsymbols.com/all/
Then double click copy and paste the desired symbol in your status.

6. Post Facebook update in blue

Paste the below mentioned code in your status update box and write your text in place of 'your text':
@@[1:[0:1: your text]]

Source - http://www.efytimes.com/e1/fullnews.asp?edid=106004&ntype=mor&edate=5/14/2013

Tuesday, May 7, 2013

Search algorithms time complexity table

Searching

Algorithm	Data Structure	Time Complexity		Space Complexity
		Average	Worst	Worst
Depth First Search (DFS)	Graph of \|V\| vertices and \|E\| edges	`-`	`O(\|E\| + \|V\|)`	`O(\|V\|)`
Breadth First Search (BFS)	Graph of \|V\| vertices and \|E\| edges	`-`	`O(\|E\| + \|V\|)`	`O(\|V\|)`
Binary search	Sorted array of n elements	`O(log(n))`	`O(log(n))`	`O(1)`
Linear (Brute Force)	Array	`O(n)`	`O(n)`	`O(1)`
Shortest path by Dijkstra, using a Min-heap as priority queue	Graph with \|V\| vertices and \|E\| edges	`O((\|V\| + \|E\|) log \|V\|)`	`O((\|V\| + \|E\|) log \|V\|)`	`O(\|V\|)`
Shortest path by Dijkstra, using an unsorted array as priority queue	Graph with \|V\| vertices and \|E\| edges	`O(\|V\|^2)`	`O(\|V\|^2)`	`O(\|V\|)`
Shortest path by Bellman-Ford	Graph with \|V\| vertices and \|E\| edges	`O(\|V\|\|E\|)`	`O(\|V\|\|E\|)`	`O(\|V\|)`

Thursday, April 18, 2013

C/C++ interview question --- question 3

Why we define pointer with a type in C?

A pointer only contains an address then why do we need different data types for it ? why not a single data type for all pointers?

ANS:

Pointer data type is used in pointer arithmetic.

e.g. :

int * p1;
char * p2;

p1 = p1 + 1;
p2 = p2 +1;

value of p1 increases by sizeof(int) which is 2 bytes and p2 increases by sizeof(char) which is 1 bytes.

Saturday, April 13, 2013

C/C++ interview question --- question 2

What are the disadvantages of inlining all functions in C?

few reasons why it would be a bad idea:

Code size increases greatly especially when inlining large functions

Instruction caches become much less effective because you are always fetching new instructions from higher up in the memory hierarchy and never re-using instructions.

Register spilling would increase the stack usage but then, if you just had normal functions, you would have to pop/push activation records onto the stack instead of spilling. So, this last tradeoff is highly dependent on the code and the compiler.

HOW TO START PREPARATION FOR IAS

HOW TO START PREPARATION

As per your sugestions.......m discussing this query again.....

I WILL DISCUSS IT SECTION WISE........lets start wid INDIAN POLITY

Start with DD Basu nd then Subhash Kashyap by NBT.

Then “Perspectives On Indian Constitution” edited by Subhash Kashyap.

Indian Constitution At Work (NCERT Class XI textbook in political science, newer syllabus)

Politics in India since Independence( NCERT Class XII textbook in political science, newer syllabus)

Democracy in India: Issues and Challenges (NCERT Class XIIth textbook in Political science, older syllabus)

Democratic politics (NCERT Class Xth, newer syllabus)

**Modern History-

Began with ‘Modern India’ by Bipin Chandra, supplemented by ‘India’s struggle for Independence’ by Bipin Chandra, Mukherjee, Panikkar. Spectrum’s book on Modern India

For Ancient India, :::-- ‘Ancient India’ by R.S. Sharma (a wonderfully concise book where every single word is important) and supplemented sparsely by
‘TheWonder that was India’ by A.L. Basham.
For Medieval India, Satish Chandra’s two volumes on Medieval India quite sufficient.

Apart from this, another famous standard text is ‘An Advanced History of India’ by Majumdar, Raychaudhuri and Dutta.

--Geography

Mapping has come out to be a real challenge in recent years. The strategy to handle India map question is again practice. What one should do is to practice map everyday for one hour. Start from mountains first day, then rivers, then waterfalls and then important cities and so on. Also mark important places which are in news from news paper. Regular practice of mapping will make you more confidant. Go through atlas also

Magzine 'Geography and you' is must read, ‘Geography And You’ is available in printed as well as PDF format.

For general geography and world geography the same wizard book on geography will be more than sufficient. Special editions on these topics are published in Competition Wizard magazine which can be helpful for quick revision (only for prelims)

Indian Economy Special Issue by Pratiyogita Darpan especially for prelims.

For reference- Indian Economy by Mishra and Puri.

International affairs/ Bilateral Issues-

Contemporary World Politics( Class XIIth NCERT)

International relations chapters in the book

Democracy in India: Issues and Challenges (NCERT Class XIIth textbook in Political Science, older syllabus)

Science and technology

Science and technology section is very vast and unpredictable. . Whatever can be covered from newspapers should be done. Defence, environment, nuclear and space science are some important sections which need special emphasis.

Monthly Magzines
Pritiyogita Darpan (PD), Competition wizard and Civil services times

As far as newspaper is concerned, HINDU is ultimate

Best way to do calculations on linux console

I always used shell to do all calculation stuff but using it can be sometimes can be a little tricky.

Then I came across python doing calculations on python is very very simple.

Example :

console[1] python
Python 2.4.3 (#1, Dec 22 2011, 12:12:01)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-50)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> t1 = 32*60 +8.1
>>> t2 = 33 *60 +35.1
>>> (t2-t1)/t2
0.043174036027988687
>>>

So you just have to type python and start doing calculations.

Friday, April 12, 2013

command to view memory and processor details in linux

To view cpu info and memory info in linux you can simply cat the related proc files.

cat /proc/cpuinfo -- for cpuinfo

cat /proc/meminfo -- for memory info
For example :

the command :
cat /proc/cpuinfo

will give output :

cat /proc/cpuinfo

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 0
siblings        : 4
core id         : 0
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6004.26
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 1
siblings        : 4
core id         : 4
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6000.25
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 2
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 0
siblings        : 4
core id         : 2
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6043.37
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 3
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 1
siblings        : 4
core id         : 6
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6000.28
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 4
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 0
siblings        : 4
core id         : 1
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6000.17
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 5
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 1
siblings        : 4
core id         : 5
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6000.25
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 6
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 0
siblings        : 4
core id         : 3
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6000.20
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:
processor       : 7
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Intel(R) Xeon(R) CPU           E5450 @ 3.00GHz
stepping        : 10
cpu MHz         : 3000.114
cache size      : 6144 KB
physical id     : 1
siblings        : 4
core id         : 7
cpu cores       : 4
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm pni monitor ds_cpl est tm2 cx16 xtpr lahf_lm
bogomips        : 6000.24
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:

Hard Disk Drive (HDD) not working on windows 7 after formatting it on Ubuntu ?

I formatted my Western Digital 500 Gb hard disk on Ubuntu 10.4 and now I want to use it on Windows 7 but it cannot detect it.
I formatted it with FAT(applicable to all) option.
I tried to Google this problem a bit and as suggested by one of the site i tried to format this drive with NTFS. Still windows cannot detect it.
Drives in windows 7 is not a problem because I tried a different usb drive on it and it works.
I can see the led of the drive glow when I connect it and I can also see remove drive safely option in lower right corner, but i cannot see any option in "my computer" to access the hard disk.

Solution:

I tried to format my HDD using "diskpart" utility available on widows7. It is working now.
Just run "diskpart" on command-promt on diskpart select your HDD and run following commands:

CLEAN
CREATE PARTITION PRIMARY 
SELECT PARTITION 1
ACTIVE
FORMAT FS=FAT32 QUICK
ASSIGN
EXIT

Sunday, April 7, 2013

CODE : ALU Arithmatic Logic Unit VHDL

This code is just an example for more detailed understanding of VHDL concepts I would recommend these two books :

1) A VHDL PRIMER by J. Bhasker - A VHDL PRIMER from flipkart.com
A VHDL PRIMER from amazon.com
A VHDL PRIMER from amazon.in

2)VHDL:PROGRAMMING BY EXAMPLES by PERRY - VHDL:PROGRAMMING BY EXAMPLES by PERRY from flipkart.com
VHDL:PROGRAMMING BY EXAMPLES by PERRY from amazon.com
VHDL:PROGRAMMING BY EXAMPLES by PERRY from amazon.in

CODE : ALU

----------------------------------------------------------------------------------
-- Company:
-- Engineer:
--
-- Create Date:    23:35:34 11/01/2006
-- Design Name:
-- Module Name:    alu_code - Behavioral
-- Project Name:
-- Target Devices:
-- Tool versions:
-- Description:
--
-- Dependencies:
--
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
--
----------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity alu_code is
    Port ( A : in STD_LOGIC_VECTOR (3 downto 0);
           B : in STD_LOGIC_VECTOR (3 downto 0);
           rst : in STD_LOGIC;
            sel : in STD_LOGIC_VECTOR (2 downto 0);
           carry : out STD_LOGIC;
           o : out STD_LOGIC_VECTOR (3 downto 0);
           en : in STD_LOGIC);
end alu_code;

architecture Behavioral of alu_code is

begin
    process(sel)
    begin
        if rst='1' then
            o<="0000";
        elsif (en='1') then
            case sel is
                when "000"=> o<=(A or B);
                when "001"=> o<=(A and B);
                when "010"=> o<=(not A);
                when "011"=> o<=(A xor B);
                when "100"=> o<=(A+B);
                                if (A+B = "1111") then
                                    carry<='1';
                                else
                                    carry<='0';
                                end if;
                when "101"=> o<=(A-B);
                                if (A<B) then
                                    carry<='1';
                                else
                                    carry<='0';
                                end if;
                when "110"=> o<=(A+1);
                                if(A="1111") then
                                    carry<='1';
                                else
                                    carry<='0';
                                end if;
                when "111"=> o<=A;
                when others => o<=A;
                                    carry<='0';
           end case;
        end if;
end process;

end Behavioral;

CODE : SIPO Serial In Parallel out register VHDL

CODE : SIPO

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----------------------------------------------------------------------------------
-- Company:
-- Engineer:
--
-- Create Date:    00:06:03 11/02/2006
-- Design Name:
-- Module Name:    SIPO_code - Behavioral
-- Project Name:
-- Target Devices:
-- Tool versions:
-- Description:
--
-- Dependencies:
--
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
--
----------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity SIPO_code is
    Port ( Din : in STD_LOGIC;
           o : out STD_LOGIC_VECTOR (3 downto 0);
           clk : in STD_LOGIC);
end SIPO_code;

architecture Behavioral of SIPO_code is

begin
process(clk)
variable temp: std_logic_vector(3 downto 0):="0000";
begin
    if(clk'event and clk='1') then
        temp(3):= temp(2);
        temp(2):= temp(1);
        temp(1):= temp(0);
        temp(0):=Din;
        o<=temp;
    end if;
end process;

end Behavioral;