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diff --git a/sliding_tile_lib.cc b/sliding_tile_lib.cc
index b43cbbaa939df7b79172ecc7a528da67ebf23d79..82402a5a185cd49453f17318705c9a81a805da77 100644 (file)
--- a/sliding_tile_lib.cc
+++ b/sliding_tile_lib.cc
@@ -118,3 +118,21 @@ std::vector<Step*> Step::successors(std::shared_ptr<Step> shared_this) {
   }
   return suc;
 }
+
+std::ostream& operator<<(std::ostream& os, const Step& step) {
+  if (step.prev != nullptr) {
+    os << *step.prev;
+    signed char this_hole = step.board.hole();
+    signed char prev_hole = step.prev->board.hole();
+    os << int(step.board.board[prev_hole]) << " ";
+    switch (this_hole - prev_hole) {
+      case -1:         os << "right";    break;
+      case  1:         os << "left";     break;
+      case -BOARD_DIM: os << "down";     break;
+      case BOARD_DIM:  os << "up";       break;
+      default:         os << "somehow!"; break;
+    }
+    os << std::endl;
+  }
+  return os;
+}

diff --git a/sliding_tile_lib.h b/sliding_tile_lib.h
index 0bd3da32cade27ab812d2e3224e08f1476bd3b0b..c92676175647c664baf9d9b804ecdda54b72beb5 100644 (file)
--- a/sliding_tile_lib.h
+++ b/sliding_tile_lib.h
@@ -30,6 +30,7 @@ struct Step {
   std::vector<Step*> successors(std::shared_ptr<Step> shared_this);
   static signed char adjacent[BOARD_SIZE][5];
 };
+std::ostream& operator<<(std::ostream& os, const Step& step);
 
 
 #endif /* _SLIDING_TILE_LIB_H */

diff --git a/sliding_tile_lib_test.cc b/sliding_tile_lib_test.cc
index aea4ab7984b10f1f14750500ab73c3a153727e01..d57c7a4d6268099dc9e09268b8a4eb9264778967 100644 (file)
--- a/sliding_tile_lib_test.cc
+++ b/sliding_tile_lib_test.cc
@@ -3,6 +3,7 @@
 #include "gtest/gtest.h"
 #include "gmock/gmock.h"
 #include <vector>
+#include <sstream>
 
 using testing::Field;
 using testing::ElementsAreArray;
@@ -136,3 +137,23 @@ TEST(Step, FourSuccessors) {
     Field(&Step::board, Field(&Board::board, ElementsAreArray({1,0,3,4,5,2,6,7,8,9,10,11,12,13,14,15}))),
     Field(&Step::board, Field(&Board::board, ElementsAreArray({1,2,3,4,5,9,6,7,8,0,10,11,12,13,14,15})))));
 }
+
+TEST(Step, Output) {
+  auto s1 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,7,11,8,9,6,0,12,13,10,14,15}}, nullptr});
+  auto s2 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,7,0,8,9,6,11,12,13,10,14,15}}, s1});
+  auto s3 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,0,7,8,9,6,11,12,13,10,14,15}}, s2});
+  auto s4 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,6,7,8,9,0,11,12,13,10,14,15}}, s3});
+  auto s5 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,0,14,15}}, s4});
+  auto s6 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,15}}, s5});
+  auto s7 = std::shared_ptr<Step>(new Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}}, s6});
+  std::ostringstream actual;
+  actual << *s7;
+  std::ostringstream expected;
+  expected << "11 down" << std::endl
+           << "7 right" << std::endl
+           << "6 up"    << std::endl
+           << "10 up"   << std::endl
+           << "14 left" << std::endl
+           << "15 left" << std::endl;
+  EXPECT_EQ(expected.str(), actual.str());
+}