From d6a3de2fd04c6d383cd924718ec5efccd944a38a Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Wed, 24 Feb 2021 22:07:48 -0500
Subject: [PATCH] Add Board.peg_count.

---
 src/pegp/board.d | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/pegp/board.d b/src/pegp/board.d
index e35df80..6a74e8a 100644
--- a/src/pegp/board.d
+++ b/src/pegp/board.d
@@ -3,6 +3,7 @@ module pegp.board;
 class Board
 {
     private int m_size;
+    private int m_peg_count;
     private bool[] m_pegs;
 
     enum Direction
@@ -42,12 +43,19 @@ class Board
         m_pegs = new bool[n_pegs];
         m_pegs[] = true;
         m_pegs[0] = false;
+        m_peg_count = n_pegs - 1;
     }
 
     this(Board b)
     {
         m_size = b.m_size;
         m_pegs = b.m_pegs.dup;
+        m_peg_count = b.m_peg_count;
+    }
+
+    @property int peg_count()
+    {
+        return m_peg_count;
     }
 
     private int peg_index(int row, int col)
@@ -78,11 +86,13 @@ class Board
     void remove_peg(Position p)
     {
         m_pegs[peg_index(p.row, p.col)] = false;
+        m_peg_count--;
     }
 
     void add_peg(Position p)
     {
         m_pegs[peg_index(p.row, p.col)] = true;
+        m_peg_count++;
     }
 
     Board move(Position p, Direction d)
@@ -103,6 +113,7 @@ class Board
     unittest
     {
         Board b = new Board(5);
+        assert(b.peg_count == 14);
         assert(b.position_valid(Position(0, 0)));
         assert(b.position_valid(4, 0));
         assert(b.position_valid(4, 4));
@@ -155,5 +166,6 @@ class Board
         assert(!b2.peg_present(2, 0));
         assert(!b2.peg_present(1, 0));
         assert(b2.peg_present(0, 0));
+        assert(b2.peg_count == 13);
     }
 }