Heapsort

Author: soumyadip007

Sorting/HeapSort.ipynb

@@ -9,39 +9,47 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "Sorted array is:\n",
-      "1\n",
+      "Sorted array is\n",
       "5\n",
+      "6\n",
       "7\n",
-      "8\n",
-      "9\n",
-      "10\n"
+      "11\n",
+      "12\n",
+      "13\n"
      ]
     }
    ],
    "source": [
-    "def partition(arr,low,high): \n",
-    "    i = ( low-1 )         \n",
-    "    pivot = arr[high]\n",
+    "def heapify(arr, n, i): \n",
+    "    largest = i \n",
+    "    l = 2 * i + 1  \n",
+    "    r = 2 * i + 2    \n",
+    "\n",
+    "    if l < n and arr[i] < arr[l]: \n",
+    "        largest = l \n",
     "  \n",
-    "    for j in range(low , high): \n",
-    "        if   arr[j] <= pivot: \n",
-    "            i = i+1 \n",
-    "            arr[i],arr[j] = arr[j],arr[i] \n",
-    "    arr[i+1],arr[high] = arr[high],arr[i+1] \n",
-    "    return ( i+1 ) \n",
+    "    if r < n and arr[largest] < arr[r]: \n",
+    "        largest = r \n",
     "  \n",
-    "def quickSort(arr,low,high): \n",
-    "    if low < high:\n",
-    "        pi = partition(arr,low,high) \n",
-    "        quickSort(arr, low, pi-1) \n",
-    "        quickSort(arr, pi+1, high) \n",
+    "    if largest != i: \n",
+    "        arr[i],arr[largest] = arr[largest],arr[i]  # swap \n",
     "  \n",
-    "\n",
-    "arr = [10, 7, 8, 9, 1, 5] \n",
+    "        heapify(arr, n, largest) \n",
+    "        \n",
+    "        \n",
+    "def heapSort(arr): \n",
+    "    n = len(arr) \n",
+    "    for i in range(n, -1, -1): \n",
+    "        heapify(arr, n, i) \n",
+    "  \n",
+    "    for i in range(n-1, 0, -1): \n",
+    "        arr[i], arr[0] = arr[0], arr[i]   # swap \n",
+    "        heapify(arr, i, 0) \n",
+    "  \n",
+    "arr = [ 12, 11, 13, 5, 6, 7] \n",
+    "heapSort(arr) \n",
     "n = len(arr) \n",
-    "quickSort(arr,0,n-1) \n",
-    "print (\"Sorted array is:\") \n",
+    "print (\"Sorted array is\") \n",
     "for i in range(n): \n",
     "    print (\"%d\" %arr[i]), "
    ]