Heaps

Author: codehariom

PQ & Heap/Heaps.py

@@ -0,0 +1,52 @@
+class Heap:
+    def __init__(self):
+        self._maxsize = 10
+        self._data = [-1] * self._maxsize
+        self._csize = 0
+
+    def __len__(self):
+        return len(self._data)
+
+    def isempty(self):
+        return len(self._data) == 0
+
+    def insert(self, e):
+        if self._csize == self._maxsize:
+            print('No Space in Heap')
+            return
+        self._csize = self._csize + 1
+        hi = self._csize
+        while hi > 1 and e > self._data[hi // 2]:
+            self._data[hi] = self._data[hi // 2]
+            hi = hi // 2
+        self._data[hi] = e
+
+    def max(self):
+        if self._csize == 0:
+            print('Heap is Empty')
+            return
+        return self._data[1]
+
+    def deletemax(self):
+        if self._csize == 0:
+            print('Heap is Empty')
+            return
+        e = self._data[1]
+        self._data[1] = self._data[self._csize]
+        self._data[self._csize] = -1
+        self._csize = self._csize - 1
+        i = 1
+        j = i * 2
+        while j <= self._csize:
+            if self._data[j] < self._data[j+1]:
+                j = j + 1
+            if self._data[i] < self._data[j]:
+                temp = self._data[i]
+                self._data[i] = self._data[j]
+                self._data[j] = temp
+                i = j
+                j = i * 2
+            else:
+                break
+        return e
+