Complete the c++ function int countEqual (const vector  :: iterator & from, const vector  :: iterator & to, int value) - Determine how many times the value appears from the 'from' iterator to the 'to' iterator. You can assume that the 'from' interator "points" to an element with an index equal to or lower than the to iterator. For example: for the vector {10, 20, 30, 20, 10} countEqual (v.begin () + 1, v.begin () + 3, 10) returns 0 countEqual (v.begin () + 0, v.begin () + 3, 10) returns 1