Copying vector elements using copy function in C++ STL
It is the method where we can insert the values of the existing vector into the newly created vector using copy() function in C++.
Syntax:
copy(first_iterator, last_iterator, back_inserter())
Example:
vector<vector<vector<int> > > v = { { { 1, 2 }, { 3, 4 } }, { { 5, 6 }, { 7, 8 } } }; // Original 3-D vector
copy(v.begin(), v.end(), back_inserter(vect)); // Copying vector elements to another vector by using copy() function
Code:
C++
#include <bits/stdc++.h>using namespace std;// function to display vectorvoid display(vector<vector<vector<int> > >& v){ for (int i = 0; i < v.size(); i++) { cout << "i : " << i << endl; for (int j = 0; j < v[i].size(); j++) { for (int k = 0; k < v[i][j].size(); k++) cout << v[i][j][k] << " "; cout << endl; } cout << endl; }}int main(){ vector<vector<vector<int> > > v = { { { 1, 2 }, { 3, 4 } }, { { 5, 6 }, { 7, 8 } } }; // initializing vect vector<vector<vector<int> > > vect; // Copying vector by copy function copy(v.begin(), v.end(), back_inserter(vect)); display(vect);} |
i : 0 1 2 3 4 i : 1 5 6 7 8
Time Complexity: O(n)
Here n is the number of elements in the original vector.
Auxiliary Space: O(n)
Initializing Vector using an Existing Vector in C++ STL
A vector is a type of container which can store objects of similar data type. Vector acts like a dynamic array where we can insert elements and the size of the array increases depending upon the elements inserted.
Syntax:
vector<data_structure/type> vector_name(size, item)
To know more about vectors refer to vectors in C++.
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