what's wrong with my copy function?

[yaoc1987]

my assignment was to implement a sequence class with dynamic array

for some reason the only error is this:
1>c:\documents and settings\joe\de sktop\spring 2010\csc 212\hw\hw #3\sequence2.cx x(53) : error C3861: 'copy': identifier not found

^there are 3 of these since i used copy 3 times

copy is part of algorithm and i did the #include<algori thm>

ive look through this code MANY MANY times and i still cant find my mistake

please someone look through this and help me spot my possibly obvious mistake! thank you!

       sequence::sequence(const sequence& source)
      {//copy constructor
      
         data = new value_type[source.capacity];
         capacity = source.capacity;
         used = source.used;
         current_index = source.current_index;
         copy(source.data, source.data + used, data);
      
      }

 void sequence::resize(size_type new_capacity)
      {//changes capacity accordingly
      
         value_type* larger_array;
      
         if(new_capacity == capacity)
            return;
      
         if(new_capacity < used)
            new_capacity = used;
      
         larger_array = new value_type[new_capacity];
         copy(data, data + used + current_index, larger_array);
         delete [] data;
         data = larger_array;
         capacity = new_capacity;
      
      }

  void sequence::operator = (const sequence& source)
      {//modify =
      
         value_type* new_data;
      
         if(this == &source)
            return;
      
         if(capacity != source.capacity)
         {
            new_data = new value_type[source.capacity];
            delete [] data;
            data = new_data;
            capacity = source.capacity;
         }
      
         used = source.used;
         current_index = source.current_index;
         copy(source.data, source.data+used, data);
      
      }

[akdemirc]

perhaps you should write the below line of code at the beginning:

using namespace std;