CODEWITHSUNDEEP
c++arraysstringvector
Merk30
Merk30

Reputation: 5

Work with vector (string) C++

I have array masiv_C0 = {{AB, ADF}, {BC, ADF}, {CD, BC}, {DE, ADF}}

I have array masiv_X0 = {{AB, ADF}, {CD, BC}, {DE, ADF}}

It is necessary to create a third array of the first two:

masiv_Y1 = masiv_C0 - masiv_X0 = {{BC, ADF}}

The problem is that in the third array which I create I delete individual elements.

As a result, rather than to obtain {{BC, ADF}} I get {{BC}} ... Help correct code! Thanks :)

#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>

using namespace std;

typedef std::vector<std::string> String1D;
typedef std::vector<String1D> String2D;

int main()
{
String2D masiv_C0(4, String1D(2));
masiv_C0[0][0]="AB";
masiv_C0[0][1]="ADF";
masiv_C0[1][0]="BC";
masiv_C0[1][1]="ADF";
masiv_C0[2][0]="CD";
masiv_C0[2][1]="BC";
masiv_C0[3][0]="DE";
masiv_C0[3][1]="ADF";

String2D masiv_X0(3, String1D(2));
masiv_X0[0][0]="AB";
masiv_X0[0][1]="ADF";
masiv_X0[0][0]="CD";
masiv_X0[0][1]="BC";
masiv_X0[0][0]="DE";
masiv_X0[0][1]="ADF";

String2D masiv_Y1 = masiv_C0;
for ( size_t i = 0; i < masiv_X0.size(); ++i)
{
    for ( size_t j = 0; j < masiv_X0[i].size(); ++j)
    {
        auto& str = masiv_X0[i][j];
        for (size_t cur = 0; cur < masiv_Y1.size(); ++cur)
        {
            auto iter = std::remove(masiv_Y1[cur].begin(), masiv_Y1[cur].end(), str);
            masiv_Y1[cur].erase(iter, masiv_Y1[cur].end());
        }
    }
}

String2D::iterator iter = masiv_Y1.begin();
while (iter != masiv_Y1.end())
{
    std::copy((*iter).begin(), (*iter).end(), std::ostream_iterator<std::string>(cout, " "));
    cout << "\n";
    ++iter;
}

return 0; }

Upvotes: 0

Views: 47

Answers (1)

user4581301
user4581301

Reputation: 33932

X-Y answer: Throw out what you are doing. The standard library does everything you need to do for you. No muss. No fuss.

#include <iostream>
#include <vector>
#include <algorithm>

int main()
{
    // shorten this templated nightmare
    using vecpair = std::vector<std::pair<std::string,std::string>>;

    // define inputs
    vecpair masiv_C0{{"AB","ADF"},{"BC","ADF"},{"CD","BC"},{"DE","ADF"}};
    vecpair masiv_X0{{"AB","ADF"},{"CD","BC"},{"DE","ADF"}};

    // define output
    vecpair masiv_Y1;

    // use std library to do the work
    std::set_difference(masiv_C0.begin(), masiv_C0.end(),
                   masiv_X0.begin(), masiv_X0.end(),
                   std::back_inserter(masiv_Y1));

    // print it.
    for (const std::pair<std::string,std::string> & p: masiv_Y1)
    {
        std::cout << "{" << p.first << "," << p.second << "}\n";
    }
    return 0;
}

Docs for std::pair

Docs for std::set_difference

Docs for std::back_inserter

Addendum note:

Everything above except the print loop should work with std::vector<std::vector<std::string>> as well should be vector of vector be an external, and performance-killing, requirement.

Upvotes: 1

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