Как быстро обучиться работать с C++?

//g++  5.4.0
 
#include <iostream>
 
void foo(int (&arr)[10])
{}
 
int main()
{
    std::cout << "Hello, world!\n";
    
    int arr[10];
    int arr2[1];
    
    foo(arr);
    //foo(arr2); //invalid initialization of reference of type ‘int (&)[10]’ from expression of type ‘int [1]’
}

#include <algorithm>
#include <ctime>
#include <deque>
#include <iostream>
#include <vector>
 
using std::cout;
using std::endl;
using std::cin;
 
const unsigned long NUM_OF_ITERATIONS = 100000;
 
void dequeTest(std::deque<int>& values)
{
    for (unsigned long iter = 0; iter < NUM_OF_ITERATIONS; iter++) {
        int sum = 0;
        for (unsigned long i = 0, size = values.size(); i < size; i += 3) {
            sum += values[i];
        }
    }
}
void vectorTest(std::vector<int>& values)
{
    for (unsigned long iter = 0; iter < NUM_OF_ITERATIONS; iter++) {
        int sum = 0;
        for (unsigned long i = 0, size = values.size(); i < size; i += 3) {
            sum += values[i];
        }
    }
}
 
int main()
{
    auto init = { 1234123, -1, 2134, 45, 5 };
    std::vector<int> vec;
    std::deque<int> deq;
 
    for (int i = 0; i < 1000; i++) {
        for (auto val : init) {
            vec.push_back(val);
            deq.push_back(val);
        }
    }
 
    clock_t start_time, end_time;
 
    start_time = clock();
    dequeTest(deq);
    end_time = clock();
    cout << "t1 = " << (end_time - start_time) << endl;
 
    start_time = clock();
    vectorTest(vec);
    end_time = clock();
    cout << "t2 = " << (end_time - start_time) << endl;
 
    return 0;
}

#include <algorithm>
#include <chrono>
#include <ctime>
#include <deque>
#include <iostream>
#include <vector>
 
using std::cout;
using std::endl;
using std::cin;
 
const unsigned long NUM_OF_ITERATIONS = 100;
 
void dequeTest(std::deque<int>& values)
{
    for (unsigned long iter = 0; iter < 1000; iter++) {
        int val = 0;
        for (unsigned long i = 0, size = values.size(); i < size; i += 3) {
            val = values[i];
        }
    }
}
void vectorTest(std::vector<int>& values)
{
    for (unsigned long iter = 0; iter < 1000; iter++) {
        int val = 0;
        for (unsigned long i = 0, size = values.size(); i < size; i += 3) {
            val = values[i];
        }
    }
}
 
int main()
{
    auto init = { 1234123, -1, 2134, 45, 5 };
    std::vector<int> vec;
    std::deque<int> deq;
 
    for (int i = 0; i < 1000; i++) {
        for (auto val : init) {
            vec.push_back(val);
            deq.push_back(val);
        }
    }
 
    std::chrono::time_point<std::chrono::high_resolution_clock> start_time, end_time;
 
    long time1 = 0;
    for (unsigned long i = 0; i < NUM_OF_ITERATIONS; i++) {
        start_time = std::chrono::high_resolution_clock::now();
        dequeTest(deq);
        end_time = std::chrono::high_resolution_clock::now();
        long elapsed = std::chrono::duration_cast<std::chrono::microseconds>(end_time - start_time).count();
 
        if (i > 10 && i < NUM_OF_ITERATIONS - 10) {
            time1 += elapsed / double(NUM_OF_ITERATIONS - 20);
        }
    }
 
    int time2 = 0;
    for (unsigned long i = 0; i < NUM_OF_ITERATIONS; i++) {
        start_time = std::chrono::high_resolution_clock::now();
        vectorTest(vec);
        end_time = std::chrono::high_resolution_clock::now();
        long elapsed = std::chrono::duration_cast<std::chrono::microseconds>(end_time - start_time).count();
 
        if (i > 10 && i < NUM_OF_ITERATIONS - 10) {
            time2 += elapsed / double(NUM_OF_ITERATIONS - 20);
        }
    }
 
    cout << "t1 = " << time1 << endl;
    cout << "t2 = " << time2 << endl;
 
    return 0;
}

double time1;

double time2;

int val = 0;
for (unsigned long i = 0, size = values.size(); i < size; i += 3) {
    val = values[i];
}