From e82316cb64f759917c00a63a1b8e02da25b0343f Mon Sep 17 00:00:00 2001
From: Vegard Storheil Eriksen <zyp@jvnv.net>
Date: Sat, 11 Dec 2010 05:29:09 +0100
Subject: Add Hand::get_breakdowns() and extend eat_*() to support it.

---
 server/hand.cpp | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 server/hand.h   |  8 ++++++
 2 files changed, 95 insertions(+), 1 deletion(-)

diff --git a/server/hand.cpp b/server/hand.cpp
index 07777fb..bc4fb7a 100644
--- a/server/hand.cpp
+++ b/server/hand.cpp
@@ -8,6 +8,14 @@ bool Hand::tenpai(const Tiles& tiles) {
 	return basic_format_tenpai(tiles);
 }
 
+List<Sets> Hand::get_breakdowns(const Tiles& tiles) {
+	List<Sets> hands;
+	
+	basic_format(tiles, hands);
+	
+	return hands;
+}
+
 bool Hand::basic_format(const Tiles& tiles, bool pair_eaten) {
 	if(!tiles) {
 		return true; // All tiles eaten.
@@ -39,6 +47,40 @@ bool Hand::basic_format(const Tiles& tiles, bool pair_eaten) {
 	return false;
 }
 
+void Hand::basic_format(const Tiles& tiles, List<Sets>& hands, const Sets& hand, bool pair_eaten) {
+	if(!tiles) {
+		hands.push_back(hand);
+		return; // All tiles eaten.
+	}
+	
+	Tiles rest;
+	Sets new_hand;
+	
+	if(!pair_eaten) {
+		rest = tiles;
+		new_hand = hand;
+		if(eat_pair(rest, new_hand)) {
+			basic_format(rest, hands, new_hand, true);
+		}
+	}
+	
+	if(tiles.size() < 3) {
+		return;
+	}
+	
+	rest = tiles;
+	new_hand = hand;
+	if(eat_pon(rest, new_hand)) {
+		basic_format(rest, hands, new_hand, pair_eaten);
+	}
+	
+	rest = tiles;
+	new_hand = hand;
+	if(eat_chi(rest, new_hand)) {
+		basic_format(rest, hands, new_hand, pair_eaten);
+	}
+}
+
 bool Hand::basic_format_tenpai(const Tiles& tiles, bool pair_eaten, bool wait_eaten) {
 	if(!tiles) {
 		return true;
@@ -132,6 +174,15 @@ bool Hand::eat_pair(Tiles& tiles) {
 	return false;
 }
 
+bool Hand::eat_pair(Tiles& tiles, Sets& hand) {
+	if(tiles[0] == tiles[1]) {
+		hand.push_back(Set(Set::Pair, Tiles(tiles.begin(), tiles.begin() + 2), false));
+		tiles.erase(tiles.begin(), tiles.begin() + 2);
+		return true;
+	}
+	return false;
+}
+
 bool Hand::eat_pon(Tiles& tiles) {
 	if(tiles[0] == tiles[2]) {
 		tiles.erase(tiles.begin(), tiles.begin() + 3);
@@ -140,6 +191,15 @@ bool Hand::eat_pon(Tiles& tiles) {
 	return false;
 }
 
+bool Hand::eat_pon(Tiles& tiles, Sets& hand) {
+	if(tiles[0] == tiles[2]) {
+		hand.push_back(Set(Set::Pon, Tiles(tiles.begin(), tiles.begin() + 3), false));
+		tiles.erase(tiles.begin(), tiles.begin() + 3);
+		return true;
+	}
+	return false;
+}
+
 bool Hand::eat_chi(Tiles& tiles) {
 	Tile::Set set = tiles.front().get_set();
 	int num = tiles.front().get_num();
@@ -163,4 +223,30 @@ bool Hand::eat_chi(Tiles& tiles) {
 	return false;
 }
 
-
+bool Hand::eat_chi(Tiles& tiles, Sets& hand) {
+	Tile::Set set = tiles.front().get_set();
+	int num = tiles.front().get_num();
+	
+	if(set == Tile::Honor || num > 7) {
+		// Can't be chi-ed.
+		return false;
+	}
+	
+	Tiles::iterator it1 = std::find(tiles.begin(), tiles.end(), Tile(set, num + 1));
+	if(it1 != tiles.end()) {
+		Tiles::iterator it2 = std::find(tiles.begin(), tiles.end(), Tile(set, num + 2));
+		if(it2 != tiles.end()) {
+			// We can eat a chi of tiles.
+			Tiles chi;
+			chi.push_back(tiles.front());
+			chi.push_back(*it1);
+			chi.push_back(*it2);
+			hand.push_back(Set(Set::Chi, chi, false));
+			tiles.erase(it2);
+			tiles.erase(it1);
+			tiles.erase(tiles.begin());
+			return true;
+		}
+	}
+	return false;
+}
diff --git a/server/hand.h b/server/hand.h
index 879bc8d..b7ae8d2 100644
--- a/server/hand.h
+++ b/server/hand.h
@@ -2,6 +2,7 @@
 #define HAND_H
 
 #include "../common/tile.h"
+#include "../common/set.h"
 
 namespace Hand {
 	//! Check if the tiles constitute a complete hand. Also valid for the concealed part of an open hand.
@@ -10,8 +11,12 @@ namespace Hand {
 	//! Check if the tiles miss only one from constituting a complete hand. Also valid for the concealed part of an open hand.
 	bool tenpai(const Tiles& tiles);
 	
+	//! Get list of possible breakdowns of a complete hand.
+	List<Sets> get_breakdowns(const Tiles& tiles);
+	
 	// Check if the tiles is matching the normal format of one pair and rest triplets.
 	bool basic_format(const Tiles& tiles, bool pair_eaten = false);
+	void basic_format(const Tiles& tiles, List<Sets>& hands, const Sets& hand = Sets(), bool pair_eaten = false);
 	
 	// Check if the tiles is matching the normal format but missing one.
 	bool basic_format_tenpai(const Tiles& tiles, bool pair_eaten = false, bool wait_eaten = false);
@@ -24,12 +29,15 @@ namespace Hand {
 	
 	// Eat a pair from beginning of list if possible and return success flag.
 	bool eat_pair(Tiles& tiles);
+	bool eat_pair(Tiles& tiles, Sets& hand);
 	
 	// Eat a pon from beginning of list if possible and return success flag.
 	bool eat_pon(Tiles& tiles);
+	bool eat_pon(Tiles& tiles, Sets& hand);
 	
 	// Eat a chi from beginning of list if possible and return success flag.
 	bool eat_chi(Tiles& tiles);
+	bool eat_chi(Tiles& tiles, Sets& hand);
 }
 
 #endif
-- 
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