Books for Programmers (From Quora)

Books to be Read by Programmers

1. Gödel Escher Bach by Douglas Hofstadter (cognitive scientist)
2. The Metamagical Themas by Douglas Hofstadter
3. The Art of Computer Programming by Donald Knuth
4. Causality: Models, Reasoning and Inference by Judea Pearl
5. Concepts, Techniques, and Models of Computer Programming by Peter Van Roy
6. Purely Functional Data Structures by Okasaki
7. The Art of Meta Object Protocol by Gregor Kiczales
8. To Mock a Mockingbird by Raymond Smullyan

UltraEdit Compile And Execute Batch Files

Compile Batch File

@echo off

set FULL_FILENAME=%~1
set FILENAME=%~n1
set DIRNAME=%~dp1
set FILE_EXT=%~x1

echo Full File Name: %FULL_FILENAME%
echo File Name: %FILENAME%
echo File Directory: %DIRNAME%
echo File Extension: %FILE_EXT%

set CC_BIN=gcc
set CPP_BIN=g++
set GHC_BIN=ghc
set SCALA_BIN=scalac.bat

set CC_EXT=.c
set CPP_EXT=.c++
set GHC_EXT=.hs
set SCALA_EXT=.scala

REM set CPP_OPTIONS=-std=c++11
set CPP_OPTIONS=

IF /I %FILE_EXT% == %CPP_EXT% GOTO __CPPCOMPILE
IF /I %FILE_EXT% == %CC_EXT%  GOTO __CCOMPILE
IF /I %FILE_EXT% == %GHC_EXT% GOTO __HSKCOMPILE
IF /I %FILE_EXT% == %SCALA_EXT% GOTO __SCALACOMPILE
GOTO END

:__CCOMPILE
echo --- Compiling C Program ... ---
call %CC_BIN% %FULL_FILENAME%  -o %FILENAME%.exe & IF ERRORLEVEL 1 (echo. && echo "ERROR - Compilation Error - Please Fix !!!" ) ELSE echo "Compilation success !!!"
GOTO END

:__CPPCOMPILE
echo --- Compiling C++ Program ... ---
call %CPP_BIN% %FULL_FILENAME%  -o %FILENAME%.exe %CPP_OPTIONS% & IF ERRORLEVEL 1 (echo. && echo "ERROR - Compilation Error - Please Fix !!!" ) ELSE echo "Compilation success !!!"
GOTO END

:__HSKCOMPILE
echo --- Compiling Haskell Program ... ---
call %GHC_BIN% --make %FULL_FILENAME%  -o %FILENAME%.exe & IF ERRORLEVEL 1 (echo. && echo "ERROR - Compilation Error - Please Fix !!!" ) ELSE echo "Compilation success !!!"
GOTO END

:__SCALACOMPILE
echo --- Compiling Scala Program ... ---
call %SCALA_BIN% %FULL_FILENAME%  & IF ERRORLEVEL 1 (echo. && echo "ERROR - Compilation Error - Please Fix !!!" ) ELSE echo "Compilation success !!!"
GOTO END

:END

Execute Batch File

@echo off

set FULL_FILENAME=%~1

set FILENAME=%~n1

set DIRNAME=%~dp1

set FILE_EXT=%~x1

echo ++++++++++++++++++++++++++++++++++++++++

echo Executing  %FULL_FILENAME%  ...

echo ++++++++++++++++++++++++++++++++++++++++

set CC_BIN=gcc

set CPP_BIN=g++

set GHC_BIN=ghc

set RUBY_BIN=C:\Ruby21\bin\ruby.exe

set PYTHON_BIN=C:\Python27\python.exe

set SCALA_BIN=scala.bat

set CC_EXT=.c

set CPP_EXT=.c++

set GHC_EXT=.hs

set PY_EXT=.py

set RUBY_EXT=.rb

set SCALA_EXT=.scala

IF /I %FILE_EXT% == %CPP_EXT% GOTO __CPPEXEC

IF /I %FILE_EXT% == %CC_EXT%  GOTO __CEXEC

IF /I %FILE_EXT% == %GHC_EXT% GOTO __HSKEXEC

IF /I %FILE_EXT% == %PY_EXT% GOTO __PYTHONEXEC

IF /I %FILE_EXT% == %RUBY_EXT% GOTO __RUBYEXEC

IF /I %FILE_EXT% == %SCALA_EXT% GOTO __SCALAEXEC

GOTO END

:__CEXEC

call %FILENAME%.exe

GOTO END

:__CPPEXEC

call %FILENAME%.exe

GOTO END

:__HSKEXEC

call %FILENAME%.exe

GOTO END

:__PYTHONEXEC

call %PYTHON_BIN% %FULL_FILENAME%

GOTO END

:__RUBYEXEC

call %RUBY_BIN% %FULL_FILENAME%

GOTO END

:__SCALAEXEC

call %SCALA_BIN% %FILENAME%

GOTO END

:END

echo ++++++++++++++++++++++++++++++++++++++++

echo Execution - Completed !!!

pause

C++11 Thread Example

[thread1.c++]

#include <iostream>
#include <thread>
#include <chrono>

using namespace std;

void funThread1() {
    for (int i = 0; i < 10; ++i) {
        this_thread::sleep_for(chrono::seconds(1));
        cout<<"Thread-1"<<endl;
    }
}

void funThread2() {
    for (int i = 0; i < 10; ++i) {
        this_thread::sleep_for(chrono::seconds(1));
        cout<<"Thread-2"<<endl;
    }
}

void funThread3() {
    for (int i = 0; i < 10; ++i) {
        this_thread::sleep_for(chrono::seconds(1));
        cout<<"Thread-3"<<endl;
    }
}

int main() {
  thread t1(funThread1);
  thread t2(funThread2);
  thread t3(funThread3);

  cout<<"Main Function - wait for Threads to complete ..."<<endl;

  t1.join();
  t2.join();
  t3.join();

  return 0;
}

Compilation:

g++ -o thread1 thread1.c++ -std=c++11 -lpthread

QSort in Haskell

qsort [] = []
qsort (lst) = ((qsort lesser) ++ mid ++ (qsort greater))
                  where p = head lst
                        lesser  = [z | z<-lst, z<p]
                        greater = [z | z<-lst, z>p]
                        mid = [z | z<-lst, z==p]

main :: IO()
main = do
    putStrLn $ show (qsort [2,7,3,5,1])

QSort in Python

#! /usr/bin/python

def myqsort(lst):
    if len(lst) <= 1:
        return lst
    p = lst[0]
    return myqsort([x for x in lst if x<p]) + [x for x in lst if x==p] + myqsort([x for x in lst if x>p])


lst = myqsort([1,4,3,4,6,3,2,6,8,3,2,6,9,7])
print lst

My .vimrc file

[reemuskumar@reemuskumar-vm ~]$ cat .vimrc

set nu
set ai
set ts=4
set expandtab

highlight Type ctermfg=darkblue
highlight Statement ctermfg=darkred
highlight Function ctermfg=DarkMagenta

 [reemuskumar@reemuskumar-vm ~]$

BFS and DFS with MultiMap in C++

#include <iostream>
#include <stack>
#include <queue>
#include <map>
#include <string>

using namespace std;

template <typename type>
class graph {
    private:
        multimap<type, type> adj;
        
    public:
        void insert(type, type);
        void DFS(type);
        void BFS(type);
        void display();
};

template <typename type>
void graph<type>::insert(type e1, type e2) {
    adj.insert(make_pair(e1,e2));
    // for un-directed graphs
    adj.insert(make_pair(e2,e1));
    
}
template <typename type>
void graph<type>::display() {
    typename multimap<type, type>::iterator i;

    for(i = adj.begin(); i != adj.end();i = adj.upper_bound(i->first)) { 
        cout<<i->first;
        pair<typename multimap<type, type>::iterator, typename multimap<type, type>::iterator> val;
        val = adj.equal_range(i->first);
        typename multimap<type, type>::iterator j;
        for(j = val.first; j != val.second; j++) {
            cout<<"->"<<j->second;
        }
        cout<<endl;
    }
}

template <typename type>
void graph<type>::DFS(type dd) {
    map<type, bool> visited;
    typename multimap<type, type>::iterator i;
    stack<type> ss;
    type v;
    
    for (i = adj.begin(); i != adj.end();i = adj.upper_bound(i->first)) {
        visited[i->first] = false;
    }
    cout<<"DFS : ";
    ss.push(dd);
    while (!ss.empty()) {
        v = ss.top();
        ss.pop();
        if (visited[v]) continue;
        cout<<v<<"->";
        visited[v] = true;
        pair<typename multimap<type, type>::iterator, typename multimap<type, type>::iterator> val;
        val = adj.equal_range(v);
        for(i = val.first; i != val.second; i++) {
            ss.push(i->second);
        }
    }
    cout<<"NULL"<<endl;
}

template <typename type>
void graph<type>::BFS(type dd) {
    map<type, bool> visited;
    typename multimap<type, type>::iterator i;
    queue<type> qq;
    type v;
    
    for (i = adj.begin(); i != adj.end();i = adj.upper_bound(i->first)) {
        visited[i->first] = false;
    }
    cout<<"BFS : ";
    qq.push(dd);
    cout<<dd<<"->";
    visited[dd] = true;
    while (!qq.empty()) {
        v = qq.front();
        qq.pop();
        pair<typename multimap<type, type>::iterator, typename multimap<type, type>::iterator> val;
        val = adj.equal_range(v);
        for(i = val.first; i != val.second; i++) {
            if (visited[i->second]) continue;
            qq.push(i->second);
            cout<<i->second<<"->";
            visited[i->second] = true;
        }
    }
    cout<<"NULL"<<endl;
}


int main() {
    graph<int> g;
    
    g.insert(1,2); g.insert(1,7); g.insert(1,8);
    g.insert(2,3); g.insert(2,6);
    g.insert(3,4); g.insert(3,5);
    g.insert(8,9); g.insert(8,12);
    g.insert(9,10); g.insert(9,11);
    g.display();
    g.DFS(1);
    g.BFS(1);
    return 0;
}

-----


++++ Output ++++
1->2->7->8
2->1->3->6
3->2->4->5
4->3
5->3
6->2
7->1
8->1->9->12
9->8->10->11
10->9
11->9
12->8
DFS : 1->8->12->9->11->10->7->2->6->3->5->4->NULL
BFS : 1->2->7->8->3->6->9->12->4->5->10->11->NULL

--------------------------------
Process exited after 0.02219 seconds with return value 0
Press any key to continue . . .