Added binary heap and heap sort

Author: das-jishu

Searching-and-sorting/heap-sort.py

@@ -0,0 +1,68 @@
+
+# MIN HEAP IMPLEMENTATION
+
+class BinaryHeap(object):
+    def __init__(self):
+        self.heap = [0]
+        self.size = 0
+
+    def insert(self, n):
+        self.heap.append(n)
+        self.size += 1
+        self.percolateUp(self.size)
+
+    def deleteMin(self):
+        self.heap[1] = self.heap[self.size]
+        self.size -= 1
+        self.heap.pop()
+        self.percolateDown(1)
+       
+    def percolateUp(self, i):
+        while i // 2 > 0:
+            if self.heap[i] < self.heap[i // 2]:
+                t = self.heap[i]
+                self.heap[i] = self.heap[i // 2]
+                self.heap[i // 2] = t
+            i = i // 2
+
+    def percolateDown(self, i):
+        while i * 2 <= self.size:
+            minChild = self.findMinChild(i)
+            if self.heap[i] > self.heap[minChild]:
+                t = self.heap[i]
+                self.heap[i] = self.heap[minChild]
+                self.heap[minChild] = t
+            i = i * 2
+
+    def findMinChild(self, i):
+        if i * 2 + 1 > self.size:
+            return i * 2
+        if self.heap[i * 2] < self.heap[i * 2 + 1]:
+            return i * 2
+        return i * 2 + 1
+
+    def buildHeap(self, l):
+        i = len(l) // 2
+        self.heap = [0] + l[:]
+        self.size = len(l)
+        while i > 0:
+            self.percolateDown(i)
+            i -= 1
+        #return self.heap
+
+def heapSort(arr):
+    b = BinaryHeap()
+    b.buildHeap(arr)
+    arr.clear()
+    end = b.size
+    while end > 0:
+        arr.append(b.heap[1])
+        b.deleteMin()
+        end -= 1
+    print(arr)
+
+if __name__ == "__main__":
+    arr = [3, 2, 5, 7, 0, 2, 9, 1, 7, 6, 4]
+    print(arr)
+    heapSort(arr)
+

Trees/implementing-binary-heap.py

@@ -0,0 +1,66 @@
+
+# MIN HEAP IMPLEMENTATION
+
+class BinaryHeap(object):
+    def __init__(self):
+        self.heap = [0]
+        self.size = 0
+
+    def insert(self, n):
+        self.heap.append(n)
+        self.size += 1
+        self.percolateUp(self.size)
+
+    def deleteMin(self):
+        self.heap[1] = self.heap[self.size]
+        self.size -= 1
+        self.heap.pop()
+        self.percolateDown(1)
+
+    def percolateUp(self, i):
+        while i // 2 > 0:
+            if self.heap[i] < self.heap[i // 2]:
+                t = self.heap[i]
+                self.heap[i] = self.heap[i // 2]
+                self.heap[i // 2] = t
+            i = i // 2
+
+    def percolateDown(self, i):
+        while i * 2 <= self.size:
+            minChild = self.findMinChild(i)
+            if self.heap[i] > self.heap[minChild]:
+                t = self.heap[i]
+                self.heap[i] = self.heap[minChild]
+                self.heap[minChild] = t
+            i = i * 2
+
+    def findMinChild(self, i):
+        if i * 2 + 1 > self.size:
+            return i * 2
+        if self.heap[i * 2] < self.heap[i * 2 + 1]:
+            return i * 2
+        return i * 2 + 1
+
+    def buildHeap(self, l):
+        i = len(l) // 2
+        self.heap = [0] + l[:]
+        self.size = len(l)
+        while i > 0:
+            self.percolateDown(i)
+            i -= 1
+
+if __name__ == "__main__":
+    b = BinaryHeap()
+    b.insert(5)
+    b.insert(4)
+    b.insert(7)
+    b.insert(1)
+    b.insert(0)
+    b.insert(9)
+    b.insert(2)
+    print("Heap", b.heap)
+    b.deleteMin()
+    print("After deleting", b.heap)
+    b.buildHeap([5, 4, 7, 1, 0, 9, 2])
+    print("Building heap from list:", b.heap)
+