mgarg1

//using next permutation
 while(next_permutation(vec.begin(), vec.end()) ){
        // do some processing on vec
 }

//using sort
std::sort (myvector.begin(), myvector.begin()+4)
std::sort (myvector.begin(), myvector.end())

//intialise vector with another array

mgarg1

vector<char> toVector( const std::string& s ) {
  string s = "apple";  
  vector<char> v(s.size()+1);
  memcpy( &v.front(), s.c_str(), s.size() + 1 );
  return v;
}
vector<char> v = toVector(std::string("apple"));

// what you were looking for (mutable)
char* c = v.data();

mgarg1

// # define NDEBUG 
# include <assert.h> 

class array2D{
	int rows,cols.**arr;
public:
	// array2D():array2D(0,0,0){}
	array2D(int r,int c,int val):rows(r),cols(c),arr(nullptr){
		arr = new int *[rows];

mgarg1

#include <stdio.h>

int compare (const void *elem1, const void *elem2){
    return *(int*)elem1 - *(int*)elem2;
}

#define ROW 5 
#define COL 2

int main()

mgarg1

#include <iostream>
#include <cstddef>

using namespace std;

template <typename T>
class Array2D {
    public:
        Array2D(size_t nr, size_t nc) : n_rows(nr), n_cols(nc), data(new T[n_rows*n_cols]) {}
        ~Array2D() { delete [] data; }

mgarg1

template<typename FUNCTION>
inline void loop(int n, FUNCTION f) {
  for (int i = 0; i < n; ++i) {
    f(i);
  }
}
// ...
loop(5, [](int jj) { std::cout << "This is iteration #" << jj << std::endl; } );

mgarg1

#ifdef assert
#undef assert
#endif
                            
#define assert(expr,i) \
    if (!(expr)) { \
        std::cerr << "Error at line " << __LINE__ << ": " \
            <<  "assert(" #expr ");" <<"value of i: "<<i<< std::endl; \
        exit(EXIT_FAILURE); \
    }

mgarg1

C++ concepts to learn:
SFINAE
pimpl
RTTI

C++ links to learn:
https://www.pluralsight.com/a/subscribe/step1?sku=IND-M-PLUS&isTrial=true&v=a

http://www.smu.edu/Guildhall/Admissions/GuildhallPreparation/ProgrammingPreparationCourse
http://www.codeguru.com/cpp/cpp/

mgarg1

#define COMMAND(NAME)  { #NAME, NAME ## _command }
     
struct command commands[] =
{
 COMMAND (quit),
 COMMAND (help),
 ...
};

struct command

mgarg1

#include <iostream>
#include <vector>
#include <cassert>

using namespace std;

int main(){
	
	int N;
	cin >> N;