Given two vectors, find common elements between these two vectors using STL in C++.
Example:
Input:
vec1 = {1, 45, 54, 71, 76, 12},
vec2 = {1, 7, 5, 4, 6, 12}
Output: {1, 12}Input:
vec1 = {1, 7, 5, 4, 6, 12},
vec2 = {10, 12, 11}
Output: {1, 4, 12}
Approach: Common elements can be found with the help of set_intersection() function provided in STL.
Syntax:
set_intersection (InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result);
// C++ program to find common elements // between two Vectors using STL #include <bits/stdc++.h> using namespace std;
int main()
{ // Get the vector
vector< int > vector1 = { 1, 45, 54, 71, 76, 12 };
vector< int > vector2 = { 1, 7, 5, 4, 6, 12 };
// Sort the vector
sort(vector1.begin(), vector1.end());
sort(vector2.begin(), vector2.end());
// Print the vector
cout << "First Vector: " ;
for ( int i = 0; i < vector1.size(); i++)
cout << vector1[i] << " " ;
cout << endl;
cout << "Second Vector: " ;
for ( int i = 0; i < vector2.size(); i++)
cout << vector2[i] << " " ;
cout << endl;
// Initialise a vector
// to store the common values
// and an iterator
// to traverse this vector
vector< int > v(vector1.size() + vector2.size());
vector< int >::iterator it, st;
it = set_intersection(vector1.begin(),
vector1.end(),
vector2.begin(),
vector2.end(),
v.begin());
cout << "\nCommon elements:\n" ;
for (st = v.begin(); st != it; ++st)
cout << *st << ", " ;
cout << '\n' ;
return 0;
} |
Output:
First Vector: 1 12 45 54 71 76 Second Vector: 1 4 5 6 7 12 Common elements: 1, 12,