Huffman encoding, find the total number of encoded bytes

Problem description: Huffman encoding can realize the compression encoding of a text. There is a string representing the text content. What is the size of the text after Huffman encoding?

For example: "aabc"

Build a Huffman tree to know the encoding of the characters in the above string

a：1

b：00

c：01

Therefore, the Huffman code for "aabc" is "110001", which is six bytes in total.

code show as below:

#include <iostream>
using namespace std;


char str[30]; //输入的字符


struct Node
{
Node *lchild;
Node *rchild;
char c;   //字符
int value;   //字符出现的频率
bool operator < (Node &A)
{
return value < A.value;
}


}TreeNode[50];


int loc;
Node *creat()   //初始化
{
TreeNode[loc].lchild = NULL;
TreeNode[loc].rchild = NULL;
TreeNode[loc].c = NULL;
TreeNode[loc].value = 0;
return &TreeNode[loc++];
}


Node *deleteNode()
{
TreeNode[loc].lchild = NULL;
TreeNode[loc].rchild = NULL;
TreeNode[loc].c = NULL;
TreeNode[loc].value = 0;
return &TreeNode[--loc];
}


void structOriginal() //Record the frequency of each character in the input string, initialize the node
{
int len ​​= strlen(str);
for (int i = 0; i < len; i++)
{
Node *T = NULL;
if (T==NULL)
{
T = creat();
T->c = str[i];
T->value += 1;
}
for (int j = 0; j < len; j++)


{
if (j<i && T->c==str[j])
{
T = deleteNode();
break;
}
else if (j>i && T->c==str[j] )
{
T->value += 1;
}
}
}
}


int rankTreeNode() // Sort the structure array by weight; loc records the current number of nodes
{
int tree_n = loc;
for (int i = 0; i < loc-1; i++)
{
bool flag = false;
for (int j = loc-1; j > i; j--)
{
if (TreeNode[j] < TreeNode[j - 1])
{
swap(TreeNode[j].value, TreeNode[j - 1].value);
swap(TreeNode[j].c, TreeNode[j - 1].c);
flag = true;
}
}
if (flag==false)
{
return tree_n;
}
}
return tree_n;
}


/ /Construct a Huffman tree according to the node weight
Node *buildHuffmanTree(Node *T,int n) //n represents the position of the current maximum weight node
{
int count = 0;
for (int index = 0; index < n; index++)
{
count += TreeNode[index].value;
}
if (T==NULL)
{
T = creat();
T->value = count;
if (n == 1)
{
return T;
}
else
{
T->rchild = &TreeNode[--n];
T->lchild = buildHuffmanTree(T->lchild, n);
}
}
return T; //return the root node pointer
}


int main()
{
int str_n; //Number of nodes
while (cin>>str_n)
{
loc = 0;
Node *T = NULL; //The root node of Huffman tree is empty
cin >> str;
structOriginal();
int tree_count = rankTreeNode(); //tree_count is to remove duplicate nodes, the actual number of nodes involved in sorting
T = buildHuffmanTree(T, tree_count); //the root node of Huffman tree
int tree_length = 0; //tree height
int ret = 0; //result
while (T->rchild!=NULL)
{
tree_length++;
ret += tree_length*(T->rchild)->value;
T = T->lchild;
}
ret += tree_length*(T->value);
cout << ret << endl;
}
return 0;

}

Rough code a bit, not perfect, please correct me.