best way to go about this?

[codrgi]

i have a group of random numbers ranging from 1 - 10000 in a list, i want to arrange that whole list by descending order, what is the best ways to do this?

[Cubbi]

list is able to sort itself: http://www.cplusplus.com/reference/stl/list/sort/ , although for descending order, you will need to use something like std::greater as the sorting predicate

[codrgi]

i want to sort by comparing pIndex->ValueToCompare, how is that done by sort??

[Cubbi]

Here's a working example (works with gcc and clang++, but the function Pred will work in any compiler)

#include <iostream>
#include <list>
#include <random>

int GenrateRandNumber(int min, int max)
{
    static std::random_device seed;
    static std::mt19937 gen(seed());
    return std::uniform_int_distribution<>(min, max)(gen);
}

struct  RANDOM_NUMBERORDER
{
        short   sIndex;
        int ValueToCompare;
};

bool Pred(const RANDOM_NUMBERORDER* left, const RANDOM_NUMBERORDER* right)
{
    return left->ValueToCompare > right->ValueToCompare;
}

int main()
{
    std::list<RANDOM_NUMBERORDER*> m_ComparationList;
    int i=0;

    while(i < 10000)
    {
        RANDOM_NUMBERORDER* pIndex = new RANDOM_NUMBERORDER;
        pIndex->sIndex = i;
        pIndex->ValueToCompare = GenrateRandNumber(1, 10000);
        m_ComparationList.push_back(pIndex);
        i++;
    }

    m_ComparationList.sort(Pred);

    for(auto p: m_ComparationList)
    {
        std::cout << p->ValueToCompare << ' ';
        delete p;
    }

}

[codrgi]

any other alternatives?

[b2ee]

Use sort() function. Assuming you are using STL's list and the number in your list is "int" type.


bool func(int x, int y)
{
return x<y;
}

sort(list.begin(), list.end(), func);


b2ee