C++Talk.NET

Jonay Aloat · Guest

I need to implement the following. Shoul I use multimap or write a string
hash class? ie

Brand Product
==========================
Samson Television
Samsung Television
Samsung VCR
Samsung DVD Player
Samsunk Television

The brand is the key and the product is the data.

If I use multimap, then I can implement it using something like this

typedef std::multimap<string, string> mmap;
typedef std::multimap<string, string>::iterator mapIter;

mmap product_map;
product_map.insert( pair<string, string> string a(Samsung), string
b(Television));
..
..
..
To find the product in brand, all I have to do is iterate using lower and
upper bound.

mapIter lowerB = product_map.lower_bound("Samsung");
mapIter upperB = product_map.upper_bound("Samsung");

for (lowerB; lowerB != upperB; ++lowerB) {
string p = (*lowerB).second;
if ( strcmp (p.c_str(), "VCR") == 0 ) ) {
//do something
} else {
//do something
}
}

Assume that I have a lot of data. Is this implementation efficient? I know
using string as the key is not a good idea. Is there a better way to do
this? Is the performance better using hash? How do I implent the hash
function.

Thanks in advance..

-Jonny