Given two arrays, find common elements between these two arrays using STL in C++.
Example:
Input: arr1[] = {1, 45, 54, 71, 76, 12}, arr2[] = {1, 7, 5, 4, 6, 12} Output: {1, 12} Input: arr1[] = {1, 7, 5, 4, 6, 12}, arr2[] = {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 Arrays using STL #include <bits/stdc++.h> using namespace std;
int main()
{ // Get the array
int arr1[] = { 1, 45, 54, 71, 76, 12 };
int arr2[] = { 1, 7, 5, 4, 6, 12 };
// Compute the sizes
int n1 = sizeof (arr1) / sizeof (arr1[0]);
int n2 = sizeof (arr2) / sizeof (arr2[0]);
// Sort the arrays
sort(arr1, arr1 + n1);
sort(arr2, arr2 + n2);
// Print the array
cout << "First Array: " ;
for ( int i = 0; i < n1; i++)
cout << arr1[i] << " " ;
cout << endl;
cout << "Second Array: " ;
for ( int i = 0; i < n2; i++)
cout << arr2[i] << " " ;
cout << endl;
// Initialise a vector
// to store the common values
// and an iterator
// to traverse this vector
vector< int > v(n1 + n2);
vector< int >::iterator it, st;
it = set_intersection(arr1, arr1 + n1,
arr2, arr2 + n2,
v.begin());
cout << "\nCommon elements:\n" ;
for (st = v.begin(); st != it; ++st)
cout << *st << ", " ;
cout << '\n' ;
return 0;
} |
Output:
First Array: 1 12 45 54 71 76 Second Array: 1 4 5 6 7 12 Common elements: 1, 12,