Write an efficient function

int first_occurrence(double x, const vector<double>& v);

that returns the position of the first occurrence of *x* in the vector *v*.
If *x* does not belong to *v*, return a -1.

Precondition

The vector *v* is sorted in nondecreasing order.

Observation You only need to submit the required procedure; your main program will be ignored.

Information

- Author
- Salvador Roura
- Language
- English
- Official solutions
- C++
- User solutions
- C++