/*
 * triangle.cpp
 *
 *  Created on: Oct 18, 2010
 *      Author: mike
 *      for use in Yale course CPSC 427a, Fall 2010
 */

#include "triangle.hpp"

// Build the triangle dictionary containing only words
// that are part of some non-trivial triangle
void Triangle::build(Dictionary& dict) {
    // Keep all words of minimal length
    const WordList& wl1 = dict.getWordList(Word::triangle_min);
    WordList::iterator p;
    for (p = wl1.begin(); p != wl1.end(); p++) {
        add(*p);
    }
    // Iterate through words in order of increasing length,
    // keeping each word only if it has a parent in the list
    // of shorter words.
    // Set the parent pointer to the first such word
    for (int k = Word::triangle_min+1; k <= Word::triangle_max; k++) {
        const WordList& wl1 = dict.getWordList(k);
        const WordList& wl2 = getWordList(k - 1);
        for (p = wl1.begin(); p != wl1.end(); p++) {
            WordEntry* parent = wl2.findParent(*p);
            if (parent != NULL) {
                // found parent, so *p in triangle
                add(*p)->setParent(parent);
            }
        }
    }
}

// Print triangle beginning with WordEntry start
ostream& Triangle::printOneTriangle(ostream& out, const WordEntry& start) const {
    for (const WordEntry* p = &start; p != NULL; p = p->getParent()) {
        out << *p << endl;
    }
    return out<< endl;
}

// Print one triangle from each Word::triangle_max-length word that has
// at least one triangle
ostream& Triangle::print(ostream& out) const {
    const WordList& wln = getWordList(Word::triangle_max);
    WordList::iterator q;
    for (q = wln.begin(); q != wln.end(); q++) {
        printOneTriangle(out, *q);
    }
    return out;
}