Added missing MaxHeap.py: Extractrd class from NNSearch_experimental.py

library/MaxHeap.py

@@ -0,0 +1,160 @@
+
+class MaxHeap:
+    def __init__(self, maxSize=None, isGreaterThan=None, smalestValue=(-1,0.0)):
+        self.heap = []
+        self.size = 0
+        self.maxSize = maxSize
+        self.isGreaterThan = isGreaterThan if isGreaterThan is not None else (lambda a, b: a > b)
+        self.smalestValue = smalestValue
+        self.indices = set()
+        self.wasChanged = False
+        self.insert(smalestValue)
+
+    def copy(self):
+        c = MaxHeap(maxSize=self.maxSize, isGreaterThan=self.isGreaterThan, smalestValue=self.smalestValue)
+        c.heap = self.heap.copy()
+        c.size = self.size
+        c.indices = self.indices.copy()
+        c.wasChanged = self.wasChanged
+        return c
+
+    def insert(self, v):
+        if self.maxSize is not None and self.size >= self.maxSize:
+            return self.replaceMax(v)
+
+        if v[0] in self.indices:
+            return False
+
+        self.indices.add(v[0])
+        pos = self.size
+        self.size += 1
+        self.heap.append(v)
+        while pos > 0:
+            w = self.heap[pos // 2]
+            if not self.isGreaterThan(v, w):
+                break
+            self.heap[pos] = w
+            pos = pos // 2
+            self.heap[pos] = v
+        self.wasChanged = True
+        return True
+
+
+    def childPos(self, pos):
+        c = (pos + 1) * 2
+        return (c - 1, c)
+
+
+    def removeMax(self):
+        if self.heap == []:
+            self.size = 0
+            return False
+        
+        x = self.heap[0]
+        self.indices.remove(x[0])
+
+        self.heap[0] = self.heap[-1]
+        self.heap = self.heap[:-1]
+        self.size -= 1
+
+        x = self.heap[0]
+        pos = 0
+        size = self.size
+
+        while pos < size:
+            (left, right) = self.childPos(pos)
+
+            if left >= size:
+                break
+
+            y = self.heap[left]
+            if right >= size:
+                if self.isGreaterThan(y, x):
+                    self.heap[pos] = y
+                    self.heap[left] = x
+                break
+
+            z = self.heap[right]
+            (best, v) = (left, y) if self.isGreaterThan(y, z) else (right, z)
+
+            if not self.isGreaterThan(v, x):
+                break
+
+            self.heap[pos] = v
+            self.heap[best] = x
+            pos = best
+
+        self.wasChanged = True
+        return True
+
+
+    def replaceMax(self, x):
+        if self.heap == []:
+            self.heap = [x]
+            self.size = 1
+            self.indices.add(x[0])
+            self.wasChanged = True
+            return True
+        
+        if x[0] in self.indices:
+            return False
+
+        if self.isGreaterThan(x, self.heap[0]):
+            return False
+
+        self.indices.remove((self.heap[0])[0])
+        self.indices.add(x[0])
+        self.heap[0] = x
+        pos = 0
+        size = len(self.heap)
+
+        while pos < size:
+            (left, right) = self.childPos(pos)
+
+            if left >= size:
+                break
+
+            y = self.heap[left]
+            if right >= size:
+                if self.isGreaterThan(y, x):
+                    self.heap[pos] = y
+                    self.heap[left] = x
+                break
+
+            z = self.heap[right]
+            (best, v) = (left, y) if self.isGreaterThan(y, z) else (right, z)
+
+            if not self.isGreaterThan(v, x):
+                break
+
+            self.heap[pos] = v
+            self.heap[best] = x
+            pos = best
+
+        self.wasChanged = True
+        return True
+
+    def getMax(self):
+        if self.heap == []:
+            return self.smalestValue
+        return self.heap[0]
+
+
+    def setMaxSize(self, maxSize):
+        self.maxSize = maxSize
+        while self.size > maxSize:
+            self.removeMax()
+
+    def toArray(self, mapFn=None):
+        return list(self.indices)
+
+    def toOrderedArray(self):
+        c = self.copy()
+        result = []
+        while c.size > 0:
+            result.append(c.getMax())
+            c.removeMax()
+        return result.reverse()
+
+    def length(self):
+        return self.size