C++: Comparing two vectors

Question

Is there any way to compare two vectors?

if (vector1 == vector2)
    DoSomething();

Note: Currently, these vectors are not sorted and contain integer values.

Answer 1

Check std::mismatch method of C++.

comparing vectors has been discussed on DaniWeb forum and also answered.

C++: Comparing two vectors

Check the below SO post. will helpful for you. they have achieved the same with different-2 method.

Compare two vectors C++

Answer 2

Your code (vector1 == vector2) is correct C++ syntax. There is an == operator for vectors.

If you want to compare short vector with a portion of a longer vector, you can use theequal() operator for vectors. (documentation here)

Here's an example:

using namespace std;

if( equal(vector1.begin(), vector1.end(), vector2.begin()) )
    DoSomething();

Answer 3

According to the discussion here you can directly compare two vectors using

==

if (vector1 == vector2){
   //true
}
else{
   //false
}

Answer 4

If they really absolutely have to remain unsorted (which they really don't.. and if you're dealing with hundreds of thousands of elements then I have to ask why you would be comparing vectors like this), you can hack together a compare method which works with unsorted arrays.

The only way I though of to do that was to create a temporary vector3 and pretend to do a set_intersection by adding all elements of vector1 to it, then doing a search for each individual element of vector2 in vector3 and removing it if found. I know that sounds terrible, but that's why I'm not writing any C++ standard libraries anytime soon.

Really, though, just sort them first.