treewars/gamevertex.cpp

#include "gamevertex.h"
#include <algorithm>
#include <cassert>

GameVertex::GameVertex(int x, int y, int z, int r, int colour, int score,
		       VertexType type, Player* player)
    : Vertex(x, y, z, r, colour, score)
{
    this->type = type;
    this->player = player;
}


float GameVertex::calculate_armor()
{
    float str = calculate_strength();
    float armor;

    switch(type)
    {
    case VERTEX_ATTACKER:
	armor = str / 10;
	break;
    case VERTEX_DEFENDER:
	armor = str / 5;
	break;
    case VERTEX_PRODUCER:
	armor = str / 40;
	break;
    }

    if (armor < 1) armor = 1;
    return armor;
}


float GameVertex::calculate_attack()
{
    float attack = calculate_strength();

    switch (type)
    {
    case VERTEX_ATTACKER:
	attack *= 1.5;
	break;
    case VERTEX_DEFENDER:
	attack /= 0.75;
	break;
    case VERTEX_PRODUCER:
	attack = 0;
	break;
    }
}


float GameVertex::calculate_strength()
{
    list<Vertex*> visited;

    // Special case - a one-node tree just returns its own score!
    if (neighbors.empty()) return (float)score;

    return calculate_strength_r(this, 0, visited);
}


// Oh the recursive recursion!
float GameVertex::calculate_strength_r(Vertex* node, unsigned int depth, list<Vertex*>& visited)
{
    // Find which vertices we need to visit from here
    list<Vertex*> neighbors = node->neighbors;
    list<Vertex*> to_visit;

    visited.push_back(node);

    for (list<Vertex*>::iterator cursor = neighbors.begin();
	 cursor != neighbors.end(); cursor++)
    {
	Vertex* v = *cursor;
	// if this is true, we haven't visited the vertex on the other end of
	// this edge yet
	if (find(visited.begin(), visited.end(), v) == visited.end())
	{
	    to_visit.push_back(v);
	}
    }

    // This is the base case - this node has no unvisited neighbors
    if (to_visit.empty())
    {
	assert(depth > 0);
	return (float)(node->score) / depth;
    }

    // Else, iterate through to_visit and visit them all, summing their
    // effective strengths adjusted for depth.
    // Since our trees are acyclic, this can't loop.
    float modscore = (float)node->score;
    if (depth > 0) modscore /= depth;

    for (list<Vertex*>::iterator cursor = to_visit.begin();
	 cursor != to_visit.end(); cursor++)
    {
	Vertex* v = *cursor;
	modscore += calculate_strength_r(v, depth+1, visited);
    }

    return modscore;
}