loserTree.hpp

/*
Approved for Public Release; Distribution Unlimited: 13-1937


Copyright (c) 2014 The MITRE Corporation. All rights reserved.

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*/

#ifndef LOSERTREE
#define LOSERTREE

#include <stdint.h>
#include <vector>
#include <cmath>

namespace snugglefish {

    using namespace std;

    //Class Declarations

    template<class comparable>
    class playerNode;
    template<class comparable>
    class matchNode;

    template<class comparable>
    struct treeElement {
        comparable value;
        playerNode<comparable>*   pNodePtr; //pointer to the player node where this should reside

        treeElement(comparable value, playerNode<comparable>* pNodePtr) {
            this-> value = value; this->pNodePtr = pNodePtr;
        }
    
        treeElement(){;}
    };

    template<class comparable>
    class treeNode{
        public:
            virtual comparable getValue() = 0; //pure virtual function
            virtual treeElement<comparable> getTreeElement() = 0;
            virtual uint8_t isPlayer() = 0;
    };

    template<class comparable>
    class playerNode: public treeNode<comparable> {
        public:
            playerNode(matchNode<comparable>* parent, std::vector<comparable>* playerList, uint32_t playerListSize, uint32_t playerId, comparable sentinel);
            comparable getValue();

            treeElement<comparable> getTreeElement() {return treeElement<comparable>(this->getValue(), this);}
            void advancePlayer() { index_id++;}
            uint8_t isPlayer() { return 1; }
            const uint32_t getId() { return this->position; }

            matchNode<comparable>* parent;

        private:
            std::vector<comparable>* player; //player for this player node
            uint32_t position; //where in the playerlist did you get the above node from?
            uint32_t index_id; //where in the list are you
            comparable sentinel;
    };


    template<class comparable>
    class matchNode: public treeNode<comparable> {
        public:
            comparable getValue() {return element.value;}
            treeElement<comparable> getTreeElement() { return this->element; }
            uint8_t isPlayer() {return 0;}

            matchNode<comparable>* parent;
            treeNode<comparable>* left;
            treeNode<comparable>* right;
            treeElement<comparable> element;
            uint32_t depth;
    };

    template<class comparable>
    class loserTree{
        public:
            loserTree(std::vector<comparable>* playerList, uint32_t listSize, comparable sentinel);
            //TODO getWinner renamed not public
            comparable getWinnerValue();
            uint32_t getWinnerId();
            void playNextMatch();
            ~loserTree();


        private:
            void removeAndPlay(treeElement<comparable>* winner);
            void buildTree();
            void destroyChildren(matchNode<comparable>* node);
            void playUp(matchNode<comparable>* node, treeElement<comparable> winner, matchNode<comparable>* winnerNode);
            treeElement<comparable> getMatchWinner(treeElement<comparable> & loser);
            treeElement<comparable> buildChildren(matchNode<comparable>* node);
            treeElement<comparable> getWinner();

            std::vector<comparable>* playerList; //array of pointers to vectors
            uint32_t playerListSize;
            uint32_t playerId; //to keep track of which vectors we've assigned

            uint32_t match_depth;
            treeElement<comparable> winner;
            matchNode<comparable>* root;
            comparable sentinel;
    };

//DEFINITIONS

    template<class comparable>
    loserTree<comparable>::loserTree(vector<comparable>* playerList, uint32_t listSize, comparable sentinel){
        //Match depth, not including players is log base 2 (listSize)
        this->sentinel = sentinel;
        this->playerList = playerList;
        this->playerListSize = listSize;
        this->playerId = 0; 
        this->match_depth = ceil(log10((double) listSize) / log10((double) 2));


        this->root = new matchNode<comparable>;
        this->root->parent = 0;
        this->root->depth = 1;

        this-> winner = this->buildChildren(this->root);

    }


    template<class comparable>
    loserTree<comparable>::~loserTree(){
        //Recursively destroy tree
        this->destroyChildren(this->root);
    }


    template<class comparable>
    treeElement<comparable> loserTree<comparable>::getWinner(){
        return this->winner;
    }

    template<class comparable>
    uint32_t loserTree<comparable>::getWinnerId(){
        return this->winner.pNodePtr->getId();
    }

    template<class comparable>
    comparable loserTree<comparable>::getWinnerValue(){
        return this->winner.value;
    }

    template<class comparable>
    void loserTree<comparable>::playNextMatch(){
        if (this->winner.pNodePtr != 0){
            this->winner.pNodePtr->advancePlayer();
            this->playUp(this->winner.pNodePtr->parent, this->winner.pNodePtr->getTreeElement(), (matchNode<comparable>*)this->winner.pNodePtr);
        }
    }

    //Starting at the deepest match node, go upwards
    template<class comparable>
    void loserTree<comparable>::playUp(matchNode<comparable>* node, treeElement<comparable> winner, matchNode<comparable>* winnerNode){
        if(node->depth == 1){  //root node
            if(winner.value > node->element.value ||
                (winner.value == node->element.value &&
                    node->right == winnerNode)){
                this->winner = node->element;
                node->element = winner;
            }else{
                this->winner = winner;
            }

        }else{
            //Compare winner received with stored loser rescurse upwards
            if(winner.value > node->element.value || 
                (winner.value == node->element.value && 
                    node->right == winnerNode)){//new loser
                this->playUp(node->parent, node->element, node);
                node->element = winner;
            }else{
                this->playUp(node->parent, winner, node);
            }
        }
    }

    template<class comparable>
    void loserTree<comparable>::destroyChildren(matchNode<comparable>* node){
        if (node->depth == this->match_depth){
            //clean up player list?
        }else{
            if(!node->isPlayer()){
                destroyChildren((matchNode<comparable>*)node->left);
                if (node->right)
                    destroyChildren((matchNode<comparable>*)node->right);
            }
        }

        if(!node->isPlayer()){
            delete node->left;
            if (node->right)
                delete node->right;
        }
    }

    template<class comparable>
    treeElement<comparable> loserTree<comparable>::buildChildren(matchNode<comparable>* node){
        treeElement<comparable> right,left;

        if (node->depth == this->match_depth || 
                this->playerId >= (this->playerListSize - 1)) { //Children are player nodes
            node->left = new playerNode<comparable>(node, this->playerList, 
                    this->playerListSize, this->playerId++, this->sentinel);
            node->right = new playerNode<comparable>(node, this->playerList, 
                    this->playerListSize, this->playerId++, this->sentinel);

            left.value = node->left->getValue();
            left.pNodePtr = (playerNode<comparable>*)node->left;

            right.value = node->right->getValue();
            right.pNodePtr = (playerNode<comparable>*)node->right;

        }else{//Regular match node where children are matches
            node->left = (treeNode<comparable>*) new matchNode<comparable>;
            matchNode<comparable>* leftMatch = (matchNode<comparable>*) node->left;
            leftMatch->parent = node;
            leftMatch->depth = node->depth + 1;

            left = this->buildChildren((matchNode<comparable>*) node->left);

            if(this->playerId >= this->playerListSize){
            //there are no more lists to sort, seed this instead
                node->right = 0;
                right = treeElement<comparable>(this->sentinel, 0);
            }else{
                node->right = (treeNode<comparable>*) new matchNode<comparable>;
                matchNode<comparable>* rightMatch = (matchNode<comparable>*) node->right;
                rightMatch->parent = node;
                rightMatch->depth = node->depth + 1;
                right = this->buildChildren((matchNode<comparable>*) node->right);
            }

        }

        if (right.value < left.value) { //right is the winner
            node->element = left; //store the loser
            return right; //return the winner
        }else{//if right => left it loses
            node->element = right;
            return left;
        } 
    }




    template<class comparable>
    playerNode<comparable>::playerNode(matchNode<comparable>* parent, vector<comparable>* playerList, uint32_t playerListSize,  uint32_t playerId, comparable sentinel){
        this->parent = parent;
        this->sentinel = sentinel;
        if(playerId >= playerListSize){//uneven 
            this->player = 0;    
        }else{
            this->player = & (playerList[playerId]);
            this->position = playerId;
        }
        this->index_id = 0;
    }


    template<class comparable>
    comparable playerNode<comparable>::getValue(){
        if(player && index_id < ((std::vector<comparable>)(*player)).size()) 
            return ((std::vector<comparable>)(*player))[index_id];
        else
             return this->sentinel;
    }






}


#endif