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lesson_2/Timer.hpp Normal file
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/*
* Timer.hpp
*
* Created on: 26 сент. 2021 г.
* Author: alexander
*/
#pragma once
#include <iostream>
#include <chrono>
class Timer
{
private:
using clock_t = std::chrono::high_resolution_clock;
using second_t = std::chrono::duration<double, std::ratio<1> >;
std::string m_name;
std::chrono::time_point<clock_t> m_beg;
double elapsed() const
{
return std::chrono::duration_cast<second_t>(clock_t::now() -m_beg).count();
}
public:
Timer() : m_beg(clock_t::now()) { }
Timer(std::string name) : m_name(name), m_beg(clock_t::now()) { }
void start(std::string name) {
m_name = name;
m_beg = clock_t::now();
}
void print() const {
std::cout << m_name << ":\t" << elapsed() * 1000 << " ms" << '\n';
}
};

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lesson_2/War_and_peace.txt Normal file

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lesson_2/main.cpp Normal file
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/*
* main.cpp
*
* Created on: 26 сент. 2021 г.
* Author: alexander
*/
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include "Timer.hpp"
using namespace std;
template<typename T>
void Swap(T *a, T *b)
{
T temp = *a;
*a = *b;
*b = temp;
}
template<typename T>
void SortPointers(vector<T*> &v)
{
sort(v.begin(), v.end(), [](const auto &v1, const auto &v2)
{
return *v1 < *v2;
});
}
void exercise_1()
{
int a(5);
int b(6);
Swap(&a, &b);
cout << a << ' ' << b << endl;
}
void exercise_2()
{
int length = 5;
vector<int*> v;
for (int i = 0; i < length; ++i)
{
int *a = new int;
*a = rand() % 10;
v.push_back(a);
}
for (int i = 0; i < length; ++i)
{
cout << *v[i] << ' ';
}
cout << endl;
SortPointers(v);
for (int i = 0; i < length; ++i)
{
cout << *v[i] << ' ';
}
cout << endl;
}
namespace counting
{
const string_view vowels
{ "AEIOUaeiou" };
void way1(const string_view &s)
{
Timer timer("Counting vowels [way 1]");
size_t count = count_if(s.begin(), s.end(), [&](const auto &c)
{
return vowels.find(c) != string::npos;
});
cout << count << endl;
timer.print();
}
void way2(const string_view &s)
{
Timer timer("Counting vowels [way 2]");
size_t count = count_if(s.begin(), s.end(), [&](const auto &c)
{
for (size_t i = 0; i < vowels.size(); ++i)
{
if (vowels[i] == c)
return true;
}
return false;
});
cout << count << endl;
timer.print();
}
void way3(const string_view &s)
{
size_t count = 0;
Timer timer("Counting vowels [way 3]");
for (size_t i = 0; i < s.size(); ++i)
{
if (vowels.find(s[i]) != string::npos)
{
++count;
}
}
cout << count << endl;
timer.print();
}
void way4(const string_view &s)
{
size_t count = 0;
Timer timer("Counting vowels [way 4]");
for (size_t i = 0; i < s.size(); ++i)
{
for (size_t j = 0; j < vowels.size(); ++j)
{
if (vowels[j] == s[i])
++count;
}
}
cout << count << endl;
timer.print();
}
}
void exercise_3()
{
ifstream file("War_and_peace.txt");
file.seekg(0, ios::end);
size_t size = file.tellg();
file.seekg(0);
string s(size, ' ');
file.read(&s[0], size);
counting::way1(s); // Counting vowels [way 1]: 59.6968 ms
counting::way2(s); // Counting vowels [way 2]: 177.219 ms
counting::way3(s); // Counting vowels [way 3]: 51.9079 ms
counting::way4(s); // Counting vowels [way 4]: 234.762 ms
}
int main()
{
// exercise_1();
// exercise_2();
exercise_3();
return 0;
}