Able to access struct member through character in c?

Question

Basically I have a struct with several members, named a-z. I have a string where I want each letter to correspond to the correct struct member. Currently I use a switch statement with each case in order to access the correct letter member of the struct, but Im wondering if theres a better (cleaner/shorter code) way to do this, without having to put 26 case statements with nearly identical code inside? My code looks somewhat like this:

typedef struct node
{
    struct node *a;
    struct node *b;
    struct node *c;
    ...
    struct node *z;
}node;

node *nTable[26][26][27];
int main
{
    ...
    
    node *nWord = malloc(sizeof(node));
    node *nPath = nWord;
    nTable[0][0][0] = nWord;

    char *cWord 
    cWord = "abcde";

    for (int n = 0; n < 5; n++)
    {
        nWord = malloc(sizeof(node));

        switch (cWord[n])
           case 'a':
               nPath->a = nWord;
               nPath = nWord;
               break;
           case 'b':
               nPath->b = nWord;
               nPath = nWord;
           ...
           case 'z':
               nPath->z = nWord;  //code is the same for each case, only difference between each is which member its assigned to
               nPath = nWord;
    }
}

Note the above code is a much reduced form of my actual code, so there may be some basic syntax and other errors within this example, but the general purpose of my code should be apparent.

So is there a cleaner way to do this, without using a case statement for each letter? Something simple like "nPath->cWord[n] = code;" would be perfect! (though this as it is, obviously does not work)

Any ideas would be great! Also sorry in advance if Ive left out any important info

Answer 1

For starters this construction

char *cWord = {a,b,c,d,e};

is syntactically invalid. You may not initialize a scalar object with a braced list with more than one initializer.

As for you question when you could declare one data member of an array type within the structure instead of numerous data members like

struct node *a;

For example

#define N 26

typedef struct node
{
    struct node *nodes[N];
} node;

And then use the following approach

const char *letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char *p = strchr( letters, toupper( ( unsigned char )cWord[i] ) );

if ( p != NULL )
{
    nPath->nodes[p - letters] = data;
    // or 
    // nPath->nodes[p - letters] = malloc( sizeof( node ) );
}

Answer 2

Maybe you can focus on the words: at first you have a linked list of words. And then there will be a linked list for every letter in order do build an array of linked lists of words. Consider this example:

#include <stdio.h>

typedef struct _node
{
    char*           word;
    struct _node*   next;
    struct _node*   prev;
};  // single node contains one word

typedef struct _node Node;

typedef struct 
{
    char        letter;
    unsigned    size;
    unsigned    limit;
    Node*       start;
    Node*       end;

}   _list;

typedef _list   Data;

In this way you have a bit more of structure

See this code

    #include "x25list.h"
    
    int main(int argc, char** argv)
    {
        Data* db[26];
        for (int i = 'a'; i < 'z'; i += 1)
        {   // builds initial linked lists
            int ix = i - 'a';
            db[ix] = (Data*)malloc(sizeof(Data));
            db[ix]->letter = i;
            db[ix]->size = 0;
            db[ix]->end = NULL;
            db[ix]->start = NULL;
        };  // for()
        return 0;
    };


In this way you have a linked list for each letter already built and start to catalog words using the notes on the lists pointed by the value of the letter minus the value of 'a'.