Write a function

int common_elements(const vector<int>& X, const vector<int>& Y);

that given two vectors *X* and *Y* in increasing order, returns
the number of common elements in the two vectors, that is, the number
of integer numbers a such that a=X[i]=Y[j] for any i and j.

Precondition

The two vectors are in strictly increasing order.

Samples

*common_elements*([3,5,7,8], [2,3,7,9,10]) = 2.

*common_elements*([1,2,3,4,5], [3,4,5,6,7,8]) = 3.

*common_elements*([1,2,3,4,5], [8,9]) = 0.

Information

- Author
- Jordi Petit
- Language
- English
- Translator
- Carlos Molina
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- C++
- User solutions
- C++