AoC18/day8p2/main.c

#include <stdio.h>

#include <glib.h>

int parse_node(gchar ***node)
{
    int children = strtol(*(*node)++, NULL, 0);
    int metadata = strtol(*(*node)++, NULL, 0);

    int values[children];
    int result = 0;

    for (int i = 0; i < children; i++) {
        values[i] = parse_node(node);
    }

    for (int i = 0; i < metadata; i++) {
        int offs = strtol(*(*node)++, NULL, 0);

        if (!children) {
            result += offs;
            continue;
        }
        if (children < offs) continue;
        result += values[offs - 1];
    }

    return result;
}

int main()
{
    gchar *contents;
    gchar **strings;
    GError *err = NULL;

    g_file_get_contents("input", &contents, NULL, &err);
    if (err) {
        fprintf(stderr, "%s\n", err->message);
        g_error_free(err);
        return 1;
    }
    strings = g_strsplit(contents, " ", -1);
    g_free(contents);

    gchar **node = strings;
    printf("%d\n", parse_node(&node));

    g_strfreev(strings);
    return 0;
}