Skip to content

Instantly share code, notes, and snippets.

@santosh
Created February 15, 2020 18:04
Show Gist options
  • Save santosh/c0190f862f02d5252c0007c24e499341 to your computer and use it in GitHub Desktop.
Save santosh/c0190f862f02d5252c0007c24e499341 to your computer and use it in GitHub Desktop.
Vectors in C++ are more or less similar to what list is in Python.
#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
vector<int> g1;
for (int i = 1; i <= 10; i++) {
g1.push_back(i * 10);
}
cout << "\nReference operator [g]: g1[2] = " << g1[2];
cout << "\nat : g1.at(4) = " << g1.at(4);
cout << "\nfront() : g1.front() = " << g1.front();
cout << "\nback() : g1.back() = " << g1.back();
// pointer to the first element
int* pos = g1.data();
cout << "\nThe first element is " << *pos;
return 0;
}
#include <iostream>
#include <vector>
using namespace std;
int main() {
vector<int> g1;
for (int i = 0; i <= 5; i++) {
g1.push_back(i);
}
cout << "Size: " << g1.size();
cout << "\nCapacity: " << g1.capacity();
cout << "\nMax Size: " << g1.max_size();
g1.resize(4);
cout << "\nSize: " << g1.size();
if (g1.empty() == false)
cout << "\nVector is not empty";
else
cout << "\nVector is empty";
g1.shrink_to_fit();
cout << "\nVector elements are: ";
for (auto it = g1.begin(); it != g1.end(); it++)
cout << *it << " ";
return 0;
}
#include <iostream>
#include <vector>
using namespace std;
int main()
{
vector<int> g1;
for (int i = 1; i <= 5; i++)
g1.push_back(i);
cout << "Output of begin and end: ";
for (auto i = g1.begin(); i != g1.end(); ++i)
cout << *i << " ";
cout << "\nOutput of cbegin and cend: ";
for (auto i = g1.cbegin(); i != g1.cend(); ++i)
cout << *i << " ";
cout << "\nOutput of rbegin and rend: ";
for (auto ir = g1.rbegin(); ir != g1.rend(); ++ir)
cout << *ir << " ";
cout << "\nOutput of crbegin and crend : ";
for (auto ir = g1.crbegin(); ir != g1.crend(); ++ir)
cout << *ir << " ";
return 0;
}
// C++ program to illustrate the modifiers in vector
#include <bits/stdc++.h>
#include <vector>
using namespace std;
int main()
{
// assign vector
vector<int> v;
// fill the array with 10 five times
v.assign(5, 10);
cout << "The vector elements are: ";
for (int i = 0; i < v.size(); i++)
cout << v[i] << " ";
// inserts 15 to the last position
v.push_back(15);
int n = v.size();
cout << "\nThe last element is : " << v[n - 1];
// removes last element
v.pop_back();
// prints the vector
cout << "\nThe vector elements are: ";
for (int i = 0; i < v.size(); i++)
cout << v[i] << " ";
// inserts 5 at the beginning
v.insert(v.begin(), 5);
cout << "\nThe first element is: " << v[0];
// removes the first element
v.erase(v.begin());
cout << "\nThe first element is: " << v[0];
// inserts at the beginning
v.emplace(v.begin(), 5);
cout << "\nThe first element is: " << v[0];
// Inserts 20 at the end
v.emplace_back(20);
n = v.size();
cout << "\nThe last element is: " << v[n - 1];
// erases the vector
v.clear();
cout << "\nVector size after erase(): " << v.size() << endl;
// two vector to perform swap
vector<int> v1, v2;
v1.push_back(1);
v1.push_back(2);
v2.push_back(3);
v2.push_back(4);
cout << "\nVector 1: ";
for (int i = 0; i < v1.size(); i++)
cout << v1[i] << " ";
cout << "\nVector 2: ";
for (int i = 0; i < v2.size(); i++) {
cout << v2[i] << " ";
}
// swaps v1 and v2
v2.swap(v1);
cout << "\nAfter Swap \nVector 1: ";
for (int i = 0; i < v1.size(); i++) {
cout << v1[i] << " ";
}
cout << "\nVector 2: ";
for (int i = 0; i < v2.size(); i++) {
cout << v2[i] << " ";
}
return 0;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment