Elements present in first array and not in second using STL in C++

// C++ simple program to 
// find elements which are 
// not present in second array 

#include <bits/stdc++.h> 
using namespace std; 

// Function for finding 
// elements which are there 
// in a[] but not in b[]. 
void findMissing(int a[], int b[], 
    int n, int m) 
{ 

 // Declare a vector to store the result 
 vector<int> v(n + m); 

 // And an iterator to traverse the vector 
 vector<int>::iterator it; 

 // Sort the given arrays 
 sort(a, a + n); 
 sort(b, b + m); 

 // Find the elements in a[] 
 // which are not in b[] 
 it = set_difference(a, a + n, b, b + m, v.begin()); 

 // Now resize the vector to the existing count 
 v.resize(it - v.begin()); 

 // Print the results 
 cout << "The elements in a[]"
  << " which are not in b[]:\n"; 
 for (it = v.begin(); it != v.end(); ++it) 
  cout << *it << " "; 
 cout << endl; 
} 

// Driver code 
int main() 
{ 
 int a[] = { 1, 2, 6, 3, 4, 5 }; 
 int b[] = { 2, 4, 3, 1, 0 }; 
 int n = sizeof(a) / sizeof(a[0]); 
 int m = sizeof(b) / sizeof(b[1]); 
 findMissing(a, b, n, m); 
 return 0; 
}