coalescence_k_ary_tree_4.cpp

#include "quetzal/coalescence.hpp"
#include <cassert>

struct vertex_info
{
    std::string field1;
    int field2;
};

int main()
{
    using edge_info = std::vector<int>;
    using tree_type = quetzal::coalescence::k_ary_tree<vertex_info, edge_info>;

    /*
     *              a
     *            /   \
     *           /     c
     *          /    / | \
     *         b    d  e  f
     */

    tree_type tree;

    // Let's attach information to the root vertex
    auto a = tree.add_vertex(vertex_info{"Im Root", 47});

    // Other vertices have default values
    auto b = tree.add_vertex(vertex_info{});
    auto c = tree.add_vertex(vertex_info{});
    auto d = tree.add_vertex(vertex_info{});
    auto e = tree.add_vertex(vertex_info{});
    auto f = tree.add_vertex(vertex_info{});

    // Attaches information to the edges from the root
    auto first_edges = tree.add_edges(a, {{b, edge_info{1, 2, 3}}, {c, edge_info{4, 5, 6}}});

    // Other edges have default values
    auto other_edges = tree.add_edges(c, {{d, edge_info{}}, {e, edge_info{}}, {f, edge_info{}}});

    assert(tree.degree(c) == 4);
    assert(tree.in_degree(c) == 1);
    assert(tree.out_degree(c) == 3);
    std::cout << "Degree of inner vertex c is " << tree.degree(c) << std::endl;

    auto root = tree.find_root_from(e);

    assert(root == a && !tree.has_predecessor(root));
    assert(tree.has_predecessor(root) == false);
    assert(tree.predecessor(c) == root);
    assert(tree.has_successors(root) == true);
    assert(std::ranges::none_of(tree.successors(c), [&](const auto &v) { return tree.has_successors(v); }));

    // Retrieve root vertex information
    std::cout << "Root first field is:\t" << tree[a].field1 << std::endl;
    std::cout << "Root other field is:\t" << tree[a].field2 << std::endl;

    // Retrieve edges information
    std::cout << "Edge (a->b) values are:\t";
    std::copy(tree[first_edges[0]].cbegin(), tree[first_edges[0]].cend(), std::ostream_iterator<int>(std::cout, " "));

    std::cout << "\nEdge (a->c) values are:\t";
    std::copy(tree[first_edges[1]].cbegin(), tree[first_edges[1]].cend(), std::ostream_iterator<int>(std::cout, " "));
    std::cout << std::endl;

    // Other edges values were left default initialized
    assert(tree[other_edges[0]].size() == 0);
}