can't deference out of range vector iterator

[onetwo12]

Mistake: can't deference out of range vector iterator.

file1.cpp

using namespace std::chrono;

int RandomNumber2() { return (std::rand() % 100); }
void experiment::FillVector(std::vector<int>& a) {
    std::srand(unsigned(std::time(0)));
    std::generate(a.begin(), a.end(), RandomNumber2);
    std::cout << "\n\nVector: ";
    for (std::vector<int>::iterator it = a.begin(); it != a.end(); it++) std::cout << *it << " ";
}

void experiment::StoogeSort(std::vector<int>& a, int start, int end) {
    int temp{0};
    if (end - start + 1 > 2) {
        temp = (end - start + 1) / 3;
        StoogeSort(a, start, end - temp);
        StoogeSort(a, start + temp, end);
        StoogeSort(a, start, end - temp);
    }
    if (a[end] < a[start]) std::swap(a[end], a[start]);
}

double experiment::measureTime(std::vector<int>& a, int n) {
    steady_clock::time_point t1 = steady_clock::now();
    StoogeSort(a, 0, n-1);
    steady_clock::time_point t2 = steady_clock::now();
    duration<double> time_span = duration_cast<duration<double>>(t2 - t1);
    double mTime = time_span.count();
    return mTime;
}


void experiment::Experiment(std::vector<int> &a, int n, int start, int end) {
    FillVector(a);
    StoogeSort(a, 0, n - 1);
    std::cout << "\n\na. Sorted data: ";
    for (int i{ 0 }; i < n; i++) std::cout << a[i] <<  ' ';

    statistics stat;

    double* times = new double[10];
    double* means = new double[10];
    double* stds = new double[10];

    std::cout << "\n";
    for (int k{0}; k<=53; k++) std::cout << "-";
    std::cout << "\nArgument" << " | " << "Average time"<< " | " << "Standard deviation of time |" << std::endl;
    for (int k{0}; k<=53; k++) std::cout << "-";

    for (n=100; n < 1000; n+=100) {
        std::cout << "\n[" << n << "]" << " ";
        for (int j{1}; j < 10; j+=1) {
            times[j] = measureTime(a, n);
        }
        means[n] = stat.meanTime(times, n);
        stds[n] = stat.stdTime(times, means[n]);
    }
}

file2.cpp

#include "statistics.h"
#include "cmath"
#include <iostream>

//Измерение среднего времени для пунктов a, b и c
double statistics::meanTime(double* t, int n) {
    double s{0};
    for (int j{1}; j < 10; j += 1) s += t[j];
    double aTime = s / 10;
    std::cout << "\t   [" << aTime << "]    \t";
    return aTime;
}

//Измерение std для пунктов a, b и c
double statistics::stdTime(double* t, double mean) {
    double s{0};
    for (int j{1}; j < 10; j += 1) s += (t[j] - mean) * (t[j] - mean);
    double sTime = sqrt(s / 10);
    std::cout << "[" << sTime << "]";
    return  sTime;
}

main.cpp

#include<iostream>
#include<vector>
#include "experiment.h"
#include <chrono>

int main() {
   

    experiment ex;
    int n{1000};
    std::vector<int> a(n);
    ex.Experiment(a, n, 0, n - 1);
   
    return 0;
}

[AbstractionAnon]

main line 11: What do you think the value of n is? It's not 1000. It is the address of the array n. You can't dimension a vector with the address of something.

Misread the braces as brackets.

[Ganado]

onetwo12, from what I can tell your issue is not in the sorting part of the code, rather it is due to a misuse of your variables. In your Experiment function, you are using 'n' for two different purposes, and this is confusing you.
- First, you use n to mean the size of the vector.
- Later, you use n as an iteration variable.

Line 41: 'means' points to a dynamic array of length 10.
Line 54: means[n] is accessed, where n >= 100.

You are going way outside the bounds of your array.
(same thing with stds array)

[onetwo12]

You are going way outside the bounds of your array.

Yes, thanks