#include <iostream>
#include <cstring>
#include <algorithm>
class MyInt {
private:
int _int;
public:
MyInt() : _int(0) {
std::cout << "Default Constructor called for " << _int << ", address: " << &_int << std::endl;
}
MyInt(int a) : _int(a) {
std::cout << "Constructor called for " << _int << ", address: " << &_int << std::endl;
}
~MyInt() {
std::cout << "Deconstructor called for " << _int << ", address: " << &_int << std::endl;
}
// Copy constructor
MyInt(const MyInt& other): _int(other._int) {
std::cout << "Copy constructor called for " << _int << ", address: " << &_int << std::endl;
}
// Move constructor
MyInt(MyInt&& other) noexcept : _int(other._int) {
std::cout << "Move constructor called for " << _int << ", address: " << &_int << std::endl;
}
void introduce() const {
std::cout << "MyInt Value: " << _int << ", address: " << &_int << std::endl;
}
MyInt& operator=(const MyInt& other) {
if (this != &other) {
_int = other._int;
}
return *this;
}
friend std::ostream& operator<<(std::ostream& os, const MyInt& obj);
};
std::ostream& operator<<(std::ostream& os, const MyInt& obj) {
os << "value: " << obj._int;
return os;
}
template<typename T>
class CustomVector {
private:
T* data;
size_t size;
size_t capacity;
void realloc(size_t newCapacity) {
T* newData = static_cast<T*>(malloc(newCapacity * sizeof(T)));
if (newData == nullptr) {
throw std::bad_alloc();
}
if (data != nullptr) {
memcpy(newData, data, size * sizeof(T));
free(data);
}
data = newData;
capacity = newCapacity;
}
public:
CustomVector() : data(nullptr), size(0), capacity(0) {}
~CustomVector() {
clear();
if (data != nullptr) {
free(data);
}
}
void push_back(const T& value) {
if (size == capacity) {
size_t newCapacity = (capacity == 0) ? 1 : capacity * 2;
realloc(newCapacity);
}
memcpy(data + size, &value, sizeof(T));
++size;
}
void pop_back() {
if (size > 0) {
--size;
}
}
T& operator[](size_t index) {
if (index >= size) {
throw std::out_of_range("Index out of range");
}
return data[index];
}
const T& operator[](size_t index) const {
if (index >= size) {
throw std::out_of_range("Index out of range");
}
return data[index];
}
size_t get_size() const {
return size;
}
size_t get_capacity() const {
return capacity;
}
void clear() {
size = 0;
}
// Custom iterator implementation
class Iterator {
private:
T* ptr;
public:
Iterator(T* p) : ptr(p) {}
T& operator*() { return *ptr; }
Iterator& operator++() { ++ptr; return *this; }
bool operator!=(const Iterator& other) const { return ptr != other.ptr; }
};
Iterator begin() { return Iterator(data); }
Iterator end() { return Iterator(data + size); }
};
// Example usage
int main() {
CustomVector<MyInt> v;
std::cout << "add fist" << std::endl;
v.push_back(MyInt(35));
for (size_t i = 0; i < v.get_size(); ++i) {
std::cout << "value: " << v[i] << ", address: " << &v[i] << std::endl;
}
std::cout << "add second" << std::endl;
v.push_back(MyInt(30));
for (size_t i = 0; i < v.get_size(); ++i) {
std::cout << "value: " << v[i] << ", address: " << &v[i] << std::endl;
}
std::cout << "add third" << std::endl;
v.push_back(MyInt(25));
for (size_t i = 0; i < v.get_size(); ++i) {
std::cout << "value: " << v[i] << ", address: " << &v[i] << std::endl;
}
std::cout << "pop back" << std::endl;
v.pop_back();
for (size_t i = 0; i < v.get_size(); ++i) {
std::cout << "value: " << v[i] << ", address: " << &v[i] << std::endl;
}
std::cout << "add fourth" << std::endl;
v.push_back(MyInt(20));
for (size_t i = 0; i < v.get_size(); ++i) {
std::cout << "value: " << v[i] << ", address: " << &v[i] << std::endl;
}
return 0;
} Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!
OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string name;
cout << "Enter name:";
getline (cin, name);
cout << "Hello " << name;
return 0;
}C++ is a widely used middle-level programming language.
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
//code
}
else {
//code
}You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression){
case value1:
// code
break; // optional
case value2:
// code
break; // optional
......
default:
code to be executed when all the above cases are not matched;
} For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
//code
} While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while (condition) {
// code
} Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition); Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.
return_type function_name(parameters);function_name (parameters)return_type function_name(parameters) {
// code
}