void assign_keys(double insert_prob,
int n_parties,
int num_keys,
std::unordered_map<key_type, std::vector<int> >& key_assignments) {
std::unordered_set<key_type> all_keys;
generate_distinct_keys(num_keys, all_keys);
assign_keys( insert_prob, n_parties, all_keys, key_assignments);
}
//---- Assign Huffman Keys to Nodes in Tree ----
double assign_keys(const void *nodes, int arity) {
struct node *root = ((struct node *) nodes);
double expected_code_length = 0;
for (int i = arity - 1; i >= 0; i--) {
if (root->children[i] != 0) {
root->children[i]->key = (double) concatenate_numbers((unsigned) root->key,(unsigned) i);
expected_code_length += assign_keys(root->children[i], arity);
} else if (root->probability != 0) {
//printf("Item with probability %f has key %d\n", root->probability, (int) root->key);
expected_code_length += (root->probability * (int) length_of_number((unsigned) root->key));
return expected_code_length;
}
}
return expected_code_length;
}
int main(int argc, char** argv) {
srand(time(NULL));
double distribution_of_characters[6] = {0};
double theoretical_distribution[] = {1.0/21, 2.0/21, 3.0/21, 4.0/21, 5.0/21, 6.0/21};
char *generated_characters = malloc(atoi(argv[argc-1])*sizeof(char));
for (int i = 2; i < 5; i++) {
int arity = i;
printf("\nArity :=\t%d\n\n", arity);
for (int i = 0; i < atoi(argv[argc-1]); i++) {
generated_characters[i] = static_gen_pmf();
distribution_of_characters[(int)(generated_characters[i] - 'a')]++; //static_gen_pmf must return values >= 'a'
}
for (int i = 0; i < sizeof(distribution_of_characters)/sizeof(*distribution_of_characters); i++) {
distribution_of_characters[i] /= (double)(atof(argv[argc-1]));
}
//---- Initialize base nodes ----
int base_nodes = arity + ceil(((sizeof(distribution_of_characters)/sizeof(*distribution_of_characters)) - (double) arity)/(arity - 1))*(arity - 1);
struct node *nodes = calloc(2 * base_nodes, sizeof(struct node));
if (!nodes) { printf("Failed to allocate memory\n"); return 1;}
for (int i = 0; i < base_nodes; i++){
if (i < (sizeof(distribution_of_characters)/sizeof(*distribution_of_characters))) {
nodes[i].probability = distribution_of_characters[i];
nodes[i].value = (i + 'a');
} else {
nodes[i].probability = 0;
}
}
//---- Create Node Tree ----
while (base_nodes != 1) {
qsort(nodes, base_nodes, sizeof(*nodes), compare_struct_node);
nodes[base_nodes].probability = 0;
for (int i = 0; i < arity; i++) {
nodes[base_nodes].probability += nodes[i].probability;
nodes[base_nodes].children[i] = &nodes[i];
nodes[base_nodes].value = (char) 0;
nodes[i].parent = &nodes[base_nodes];
}
for(int i = 0; i < arity; i++){
nodes++;
}
base_nodes -= (arity - 1);
}
//---- Calculate Entropy of PMF ----
double entropy = 0;
for (int i = 0; i < sizeof(theoretical_distribution)/sizeof(*theoretical_distribution); i++) {
entropy -= (theoretical_distribution[i] * (log10(theoretical_distribution[i])/log10(arity)));
}
printf("Entropy of Distribution:\t%f\n", entropy);
printf("Expected Average Length:\t%f\n", assign_keys(nodes, arity));
//---- Encode and decode string ----
double encoding[atoi(argv[argc-1])];
char decoded_string[atoi(argv[argc-1])];
double average_size = encode(nodes, generated_characters, sizeof(generated_characters)/sizeof(*generated_characters), encoding);
decode(nodes, encoding, sizeof(encoding)/sizeof(*encoding), decoded_string);
printf("Actual Average Length:\t\t%f\n", average_size);
for (int i = 0; i < atoi(argv[argc-1]); i++) {
if (decoded_string[i] != generated_characters[i]) break;
if (i == atoi(argv[argc-1]) - 1) printf("Successfully decoded encoded string\n");
}
}
return 0;
}
