//---- Encode a given string ----
double encode(const void *nodes, char *string, unsigned size, double *encoding) {
struct node *root = ((struct node *) nodes);
double total_size = 0;
for (int i = 0; i < (int) size; i++) {
encoding[i] = get_key(root, string[i]);
total_size += length_of_number(encoding[i]);
}
return total_size/size;
}
/* This function converts the strings to integers */
int string_to_integer(char *s){
int expn; /* The power of 10 with which to multiply values */
int len_temp; /* To temporarily store length value */
int num_temp; /* To temporarily store the number */
int i = 0; /* Counter integer for conversion loop */
int j = 0; /* Counter integer for the -vity loop */
int neg = 1; /* To capture the -vity or +vity */
int total = 0; /* Where the numbers get added to get the actual
numerical values*/
len_temp = length_of_number(s); /* Call to function for length */
/* for ridiculously long numbers */
if(len_temp > 10){
return 0;
}
expn = expo(len_temp); /* Call to function for exponent */
/* Loop to determine +vity or -vity */
while(*(s + j) != '\0'){
if(*(s + j) == '-'){
if(*(s + (j + 1)) > '9' || *(s + (j + 1)) < '0'){
/* To stop the search for numbers in the string */
break;
}
neg *= -1;
}
j++;
}
while(*(s + i) != '\0'){
/* Assign the value of (s + i) to an int variable */
num_temp = *(s + i) - 48;
if(num_temp >=0 && num_temp <= 9){
num_temp *= expn; /* Multiply by expn so that if the number
is 9 then it becomes 90 (for string '98')*/
expn /= 10; /* Divide the exponent by 10 so that the
next number (8 in string '98) is
only multiplied by 1 */
/* To check if the number is going to be greater than an int
can hold */
if(total == 2147483640 && num_temp > 7 && neg == 1){
return 0;
}
total += num_temp; /* Add the value to total */
}
i++; /* Increase the counter */
}
total *= neg; /* To convert the number to -ve */
return total;
}
//---- 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;
}
//---- Get number of digits in a number ----
unsigned length_of_number(unsigned n) {
if (n < 10) return 1;
return (1 + length_of_number(n/10));
}