TODO - Leetcode-811

/**
 * Return an array of size *returnSize.
 * Note: The returned array must be malloced, assume caller calls free().
 */

typedef struct Tree {
    char  *domain;
    int    visit;
    Tree **children;
} Tree;

void flattenTree (Tree **tree, int *idx, char **result) {
    int i;
    for (i = 0; tree[i] != NULL; i++) {
        result[idx] = ()
    }
}

char** subdomainVisits(char** cpdomains, int cpdomainsSize, int* returnSize) {
    int  count = 0;

    Tree **tree = (Tree **) malloc(sizeof(Tree *) * 300);
    memset(tree, 0, 300);

    int i, j, k;
    for (i = 0; i < cpdomainsSize; i++) {
        // map visit & domain name
        int visit;
        char *domain = (char *) malloc(sizeof(char) * 100);
        memset(domain, 0, 100);
        sscanf(cpdomains[i], "%d %s", &visit, domain);

        // divide domain into 3 parts
        char **parts = (char **) malloc(sizeof(char *) * 3);
        char  *token = strtok(domain, ".");
        int   total  = 0;
        while(token) {
            parts[total] = (char *) malloc(size(char) * 100);
            strcpy(parts[total], token);
            token = strtok(NULL, ".");
            total++;
        }

        // start from the last part
        Tree **current = tree;
        for (j = total - 1; j >= 0; j--) {
            int found = 0;
            for (k = 0; current[k] != NULL; k++) {
                // if domain matches, add counter and transverse to it's children
                // create children if doesn't exist
                if (strcmp(current[k]->domain, parts[j]) == 0) {
                    found              = 1;
                    current[k]->visit += visit;
                    current            = current[k]->children;
                    break;
                }
            }
            // if not found, append current domain to the tree
            if (!found) {
                current[k]           = (Tree *) malloc(sizeof(Tree));
                current[k]->domain   = parts[j];
                current[k]->visit    = visit;
                current[k]->children = (Tree **) malloc(sizeof(Tree) * 300);
                current              = current[k]->children;
                memset(current[k]->children, 0, 300);
            }
        }
    }


    char **result = (char **) malloc(sizeof(char) * 300);

}