#include <stdlib.h>
#include <stdio.h>

// structs
struct node2d {
    struct node1d *first;
    char *name;
    struct node2d *down;
};
struct node1d {
    struct node1d *next;
    char *name;
};

// funs in this file
struct node1d *mk1dNode(char *name, struct node1d *next);
struct node2d *mk2dNode(struct node1d *first, char *name, struct node2d *down);
struct node2d *mkExConfig ();
// external funs
void printConfig(struct node2d *p2d);
void print2dNode(struct node2d *p2d);
void print1dNode(struct node1d *p1d);

// main
int main (int argc, char *argv[]) {
    struct node2d *p2d;
    p2d = mkExConfig();
    printConfig(p2d);
    return 0;
}

struct node2d *mkExConfig() {
    struct node1d *p1d;
    struct node2d *p2d;
    
    // create rows from bottom to top
    
    // create bottom row from right to left
    p1d = mk1dNode("c3pO", NULL);
    p1d = mk1dNode("cso", p1d);
    p2d = mk2dNode(p1d, "R2D2", NULL);

    // create middle row
    p2d = mk2dNode(NULL, "alice", p2d);

    // create top row from right to left
    p1d = mk1dNode("e342", NULL);
    p1d = mk1dNode("sally", p1d);
    p1d = mk1dNode("xy2", p1d);
    p2d = mk2dNode(p1d, "joe", p2d);

    return p2d;
}

struct node1d *mk1dNode(char *name, struct node1d *next) {
    struct node1d *p1d;
    p1d = (struct node1d *)malloc(sizeof(struct node1d));
    (*p1d).next = next;   // (*p1d). is long form
    p1d->next = next;     // common abbreviation
    p1d->name = name;
    return p1d;
}

struct node2d *mk2dNode(struct node1d *first, char *name, struct node2d *down) {
    struct node2d *p2d;
    p2d = (struct node2d *)malloc(sizeof(struct node2d));
    p2d->first = first;
    p2d->name  = name;
    p2d->down  = down;
    return p2d;
}