Index Heap C++ bug fixed.

liuyubobobo · liuyubobobo · commit cf0e97829ab7 · 2018-03-02T17:21:21.000-08:00
diff --git a/04-Heap/Course Code (C++)/09-Index-Heap-Advance/main.cpp b/04-Heap/Course Code (C++)/09-Index-Heap-Advance/main.cpp
@@ -100,9 +100,13 @@ class IndexMaxHeap{
         Item ret = data[indexes[1]];
         swap( indexes[1] , indexes[count] );
         reverse[indexes[count]] = 0;
-        reverse[indexes[1]] = 1;
         count--;
-        shiftDown(1);
+
+        if(count){
+            reverse[indexes[1]] = 1;
+            shiftDown(1);
+        }
+
         return ret;
     }
 
@@ -113,9 +117,13 @@ class IndexMaxHeap{
         int ret = indexes[1] - 1;
         swap( indexes[1] , indexes[count] );
         reverse[indexes[count]] = 0;
-        reverse[indexes[1]] = 1;
         count--;
-        shiftDown(1);
+
+        if(count) {
+            reverse[indexes[1]] = 1;
+            shiftDown(1);
+        }
+
         return ret;
     }
 
diff --git a/04-Heap/Course Code (C++)/Chapter-04-Completed-Code/IndexMaxHeap.h b/04-Heap/Course Code (C++)/Chapter-04-Completed-Code/IndexMaxHeap.h
@@ -106,9 +106,13 @@ class IndexMaxHeap{
         Item ret = data[indexes[1]];
         swap( indexes[1] , indexes[count] );
         reverse[indexes[count]] = 0;
-        reverse[indexes[1]] = 1;
         count--;
-        shiftDown(1);
+
+        if(count){
+            reverse[indexes[1]] = 1;
+            shiftDown(1);
+        }
+
         return ret;
     }
 
@@ -119,9 +123,13 @@ class IndexMaxHeap{
         int ret = indexes[1] - 1;
         swap( indexes[1] , indexes[count] );
         reverse[indexes[count]] = 0;
-        reverse[indexes[1]] = 1;
         count--;
-        shiftDown(1);
+
+        if(count){
+            reverse[indexes[1]] = 1;
+            shiftDown(1);
+        }
+
         return ret;
     }
 
diff --git a/04-Heap/Course Code (C++)/Optional-3-Index-Min-Heap/IndexMinHeap.h b/04-Heap/Course Code (C++)/Optional-3-Index-Min-Heap/IndexMinHeap.h
@@ -104,9 +104,13 @@ class IndexMinHeap{
         Item ret = data[indexes[1]];
         swap( indexes[1] , indexes[count] );
         reverse[indexes[count]] = 0;
-        reverse[indexes[1]] = 1;
         count--;
-        shiftDown(1);
+
+        if(count){
+            reverse[indexes[1]] = 1;
+            shiftDown(1);
+        }
+
         return ret;
     }
 
@@ -117,9 +121,13 @@ class IndexMinHeap{
         int ret = indexes[1] - 1;
         swap( indexes[1] , indexes[count] );
         reverse[indexes[count]] = 0;
-        reverse[indexes[1]] = 1;
         count--;
-        shiftDown(1);
+
+        if(count){
+            reverse[indexes[1]] = 1;
+            shiftDown(1);
+        }
+
         return ret;
     }
 
