c - Which is the better Searching algorithm ?? -

i have 3 groups of items(names). group 1 has around 2,1k items, group 2 - around 7,6k , group 3 around 21k. need search in these groups. need hint better. thought either put in bin tree:

 gtree* t = g_tree_new((gcomparefunc)g_ascii_strcasecmp);  , search this:  goup =  g_tree_lookup(t, (gpointer *)itemname); 

or more efficient make 3 arrays of strings:

char g1[2300][14]; char g2[8000][14]; char g3[78000][14]; 

and search (not checked, pseudocode):

    int isvalueinarray(char val,  char *g[][14];, int size){         int i;         (i=0; < size; i++) {             if (memcmp(val, g[i], strlenth) == 0)                 return true;         }         return false;     }     int group=0;     if (isvalueinarray(itemname, g2, 7800) ) group = 2;     if (isvalueinarray(itemname, g1, 2300) ) group = 1; 

or there better solution that?

if want asymptotically efficient way of finding whether string in set of strings can pre-processed, can consider using a trie. construction time linear (o(l), l sum of strings lengths in 3 sets), , lookup time linear on size of string looking (which is, in case, 14).

a binary search tree nice option, giving logarithmic (on size of string sets) performance. can bit slower, easier implement. note pre-processing (inserting strings of 3 sets tree) takes n * log(n) time, n sum of set sizes.

do not use linear search in array, it's slow.