#include <iostream>
#include <vector>
struct huffman_element {
    huffman_element() {
        weight = 0;
        lchild = -1;
        rchild = -1;
        parent = -1;
    }
    double weight;
    int lchild;
    int rchild;
    int parent;
};
class huffman_tree {
public:
    explicit huffman_tree(const std::vector<double>&weight_array) {
        init_tree(weight_array);
        construct(weight_array.size());
    }
    huffman_tree(const huffman_tree &) = delete;
    const huffman_tree & operator = (const huffman_tree &) = delete;
    virtual ~huffman_tree() = default;
public:
    void print() {
        for (int i = 0;i < tree_.size();i++) {
            std::cout << "(weight:" << tree_[i].weight << ",parent:" << tree_[i].parent << ",lchild:" << tree_[i].lchild << ",rchild:" << tree_[i].rchild << ")" << std::endl;
        }
    }
private:
    void init_tree(const std::vector<double>&weight_array) {
        int n = weight_array.size();
        int size = n * 2 - 1;
        tree_.resize(size);
        for (int i = 0;i < n;i++) {
            tree_[i].weight = weight_array[i];
        }
    }
    void select_min(int size, int &index0, int &index1) {
        for (int i = 0;i < size;i++) {
            if (-1 == tree_[i].parent) {
                index0 = i;
                break;
            }
        }
        for (int i = 0;i < size;i++) {
            if (-1 == tree_[i].parent && tree_[i].weight < tree_[index0].weight) {
                index0 = i;
            }
        }
        for (int i = 0;i < size;i++) {
            if (-1 == tree_[i].parent && i != index0) {
                index1 = i;
                break;
            }
        }
        for (int i = 0;i < size;i++) {
            if (-1 == tree_[i].parent && tree_[i].weight < tree_[index1].weight && i != index0) {
                index1 = i;
            }
        }
    }
    void construct(int start) {
        int size = tree_.size();
        for (int k = start;k < size;k++) {
            int index0 = -1;
            int index1 = -1;
            select_min(k, index0, index1);
            tree_[index0].parent = k;
            tree_[index1].parent = k;
            tree_[k].lchild = index0;
            tree_[k].rchild = index1;
            tree_[k].weight = tree_[index0].weight + tree_[index1].weight;
        }
    }
private:
    std::vector<huffman_element>tree_;
};
int main() {
    std::vector<double>weight_array{ 5, 29, 7, 8, 14, 23, 3, 11 };
    huffman_tree huffman(weight_array);
    huffman.print();

    return 0;
}