[Board] Implement piece and setPiece

Board.cpp

@@ -3,17 +3,32 @@
 #include <ostream>
 #include <cassert>
 #include <cmath>
+#include <bitset>
+#include <algorithm>
 
 Board::Board() {
 }
 
 void Board::setPiece(const Square &square, const Piece::Optional &piece) {
-    (void) square;
-    (void) piece;
+
+    auto index = square.index();
+    for (auto &item : mPieceBBs) {
+        clearIndex(item, index);
+    }
+
+    setIndex(mPieceBBs[piece->typeVal() + piece->colorVal()], index);
 }
 
 Piece::Optional Board::piece(const Square &square) const {
-    (void) square;
+    int i = 0;
+    BitBoard mask = indexToBitBoard(square.index());
+    for (const auto &kPieceBb : mPieceBBs) {
+        if (kPieceBb & mask) {
+            return Piece(indexToColor(i), indexToType(i));
+        }
+
+        i++;
+    }
     return std::nullopt;
 }