CODEWITHSUNDEEP
c++classpointersvectorstruct
user6531747
user6531747

Reputation:

how to use vector and struct members in method

im new in c++ (and not to old in programming...) and i have problem with handling vectors and strucs in class. basically i have a vector and a array of pointers to struct members in the class and i want work on the in my methos but im doing something worng/

here is my movement.h

#pragma once
using namespace std;
class movement
{
private:
    static const int MAX_ROW_PER_TRACKER = 100;
    static const int MIN_TO_START_CALC = 30;
    static const int MAX_TRACKERS = 20;

    struct tracker
    {
        int id;
        double a[MAX_ROW_PER_TRACKER];
        double b[MAX_ROW_PER_TRACKER];
        double c;
    };
    vector<int> trackersOrder[MAX_TRACKERS] = {};
    tracker* trackersArr[MAX_TRACKERS];

public:
    movement();
    void addRow(int a, int b, int c);
    ~movement();
};

and my movement.cpp

#include "stdafx.h"
#include "movement.h"
#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

movement::movement()
{
}

void movement::addRow(int id, int a, int b)
{
    int index;
    vector<int>::iterator searchID = find(trackersOrder.begin(), trackersOrder.end(), ID);
    if (searchID == trackersOrder.end())
    {
        vector<int>::iterator freeLocation = find(trackersOrder.begin(), trackersOrder.end(), 0); 
        index = freeLocation - trackersOrder.begin();
        trackersOrder.insert(trackersOrder.begin + index, id);
        structArr[index] = new tracker;
        structArr[index]->id = id;
        structArr[index]->a[0] = a;
        structArr[index]->b[0] = b;
        structArr[index]->c = 0;
    }

}

movement::~movement()
{
}

so when i send to method "addRow" id, and b i want to first check if i allready have this id in my vector (the vector just give me the index for the structs array) and if not then if put the id in the first empty place in the vector and on the structs array/ but from some reasin its look to me that the methid dont reconized the vector and the structs. can you help me understand why? p.s - i can bet that i have more mistakes in my code, its my firs try with pointers and ect. (im comming from the good life in Matlab) so i will be happy to learn on them also thank you very much!

Upvotes: 1

Views: 79

Answers (1)

Christophe
Christophe

Reputation: 73376

The main problem

The problem is that in your code, trackersOrder is not a vector but an array of vectors: 

vector<int> trackersOrder[MAX_TRACKERS] = {};  // array of MAXTRACKERS vectors !!

The solution

If you define it as simple vector, it should work better: 

vector<int> trackersOrder;

If you want to set its size do it in the movement constructor: 

movement::movement() : trackersOrder(MAX_TRACKERS)
{
}

Other issues

There is a case typo with an ID that should be id.

auto searchID = find(trackersOrder.begin(), trackersOrder.end(), id);  // by the way auto is easier + ID corrected

There are a missing () after a begin whicn transforms unfortunately your iterator arithmetic into function pointer arithmetic (sic!!):

    trackersOrder.insert(trackersOrder.begin() + index, id); // corrected

Finally, there are a couple of structArr that should be replaced by trackersArr.

The result does finally compile (online demo)

Upvotes: 1

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