A huffman code length generator is available about cve-2023-4863 HOT 13 OPEN

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <assert.h>
//#include <malloc.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#define MAX_ALLOWED_CODE_LENGTH      15

//copy and paste output of this program into Graphvis
//https://dreampuf.github.io/GraphvizOnline/


void print_tree() {
    int num_nodes = 1;    // number of Huffman tree nodes
    int num_open = 1;    // number of open branches in current tree level
    uint32_t n = 1;
    
#if 1
    uint32_t count[] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 5, 9, 17, 1, 1, 3}; // size=542 //alphabet = 40, table_size = 414
#else
    uint32_t count[] = {0, 1, 1, 1, 1, 0, 1, 1, 0, 15, 5,   9,  1, 1, 1, 2}; //alphabet = 40, table_size = 410
#endif
    uint32_t has_leaf_child[65537] = {0};
    has_leaf_child[0] = 1;

    for (int len = 1; len <= MAX_ALLOWED_CODE_LENGTH; ++len) {
        num_open <<= 1;
        num_nodes += num_open;

        uint32_t leaf_count = count[len];
        uint32_t internal_count = num_open - leaf_count;
        
        for(uint32_t i = 0; i < num_open; i++) {
            uint32_t node = ((1 << len) - 1) + i;
            uint32_t parent = (node-1)/2;
            
            if(i >= internal_count) {
                while (node > 0) {
                    has_leaf_child[node] = 1;
                    node = (node-1)/2;
                }
            }
            n++;
        }
        num_open -= leaf_count;       
    }
    num_open = 1;
    num_nodes = 1;
    n = 1;

    printf("digraph BST {\n");
    for (int len = 1; len <= MAX_ALLOWED_CODE_LENGTH; ++len) {
        num_open <<= 1;
        num_nodes += num_open;

        uint32_t leaf_count = count[len];
        uint32_t internal_count = num_open - leaf_count;
        
        for(uint32_t i = 0; i < num_open; i++) {
            uint32_t node = ((1 << len) - 1) + i;
            uint32_t parent = (node-1)/2;
            if (has_leaf_child[node]) {
                printf("\tn%d [label=\"%d\"]\n", node, node);
            
                if(i >= internal_count) {
                    printf("\tn%d [shape=doublecircle]\n", node);
                }
                printf("\tn%d -> n%d [label=\"%d\"]\n", parent, node, ((i+1) % 2));
                
            }
            n++;
        }
        num_open -= leaf_count;       
    }
    printf("}\n");
}

int main(int argc, char **argv) {
    print_tree();
    return 0;
}

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <assert.h>
#include <malloc.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#define MAX_ALLOWED_CODE_LENGTH      15

//copy and paste output of this program into Graphvis
//https://dreampuf.github.io/GraphvizOnline/


void print_tree() {
    int num_nodes = 1;    // number of Huffman tree nodes
    int num_open = 1;    // number of open branches in current tree level
    uint32_t n = 1;
    
    uint32_t count[] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 5, 9, 17, 1, 1, 3};

    uint32_t symbol_count = 0;
    for(uint32_t i = 0; i <= MAX_ALLOWED_CODE_LENGTH; i++) {
        symbol_count += count[i];
    }
    
    uint32_t *leaf_nodes = malloc(sizeof(uint32_t) * symbol_count);
    uint32_t total_leaf_count = 0;

    for (int len = 1; len <= MAX_ALLOWED_CODE_LENGTH; ++len) {
        num_open <<= 1;
        num_nodes += num_open;

        uint32_t leaf_count = count[len];
        uint32_t internal_count = num_open - leaf_count;
        
        for(uint32_t i = 0; i < num_open; i++) {
            uint32_t node = ((1 << len) - 1) + i;
            if(i >= internal_count) {
                leaf_nodes[total_leaf_count++] = node;
            }
        }
        num_open -= leaf_count;       
    }
    assert(total_leaf_count == symbol_count);
    //let graphvis handle the duplicate edges
    printf("strict digraph BST {\n");

    for(uint32_t i = 0; i < total_leaf_count; i++) {
        uint32_t node = leaf_nodes[i];
        printf("\tn%d [shape=doublecircle]\n", node);
        while(node != 0) {
            uint32_t parent = (node-1)/2;
            printf("\tn%d [label=\"%d\"]\n", node, node);
            printf("\tn%d -> n%d [label=\"%d\"]\n", parent, node, ((node+1) % 2));

            node = parent;
        }
   
    }
    printf("}\n");
}

int main(int argc, char **argv) {
    print_tree();
    return 0;
}