Multimap iteration

Fri Nov 07, 2008 6:15 pm

Im currently working with multimap in C++. So for example i got a multimap like
this:

Code:: m.insert(pair<const char* const, int>("a", 1)); m.insert(pair<const char* const, int>("c", 2)); m.insert(pair<const char* const, int>("b", 3)); m.insert(pair<const char* const, int>("b", 4)); m.insert(pair<const char* const, int>("a", 5)); m.insert(pair<const char* const, int>("b", 6));

and i want to loop it but without repeating the same key eg: I want to print
average of each key and print like this

Code:: a = 3 b = 6.3 c = 2

My current solution is loop each key and find all other value with the same key.
So its like a loop in loop. But the problem is I print a twice, b three times,
and C once. How can I skip the repetition so it wont print the same key again?

Fri Nov 07, 2008 6:17 pm

If there are no memory constraints you can create a temporary map of key
& valueInfo.
valueInfo can be a structure like following...

Code:: Struct valueInfo { int val_total; int count }

Now you can fill this map while traversing your original data structure
(multimap) ...

For your example it will be

Code:: ("a", (6,2)) ("b", (13,3)) ("c", (2,1))

Once you have traversed the original data structure, you can calculate
the desired output with a single traversal of your temp map.

So it will be Loop after Loop solution instead of yours Loop in Loop

Multimap iteration

Multimap iteration

Re: Multimap iteration