Wavelet tree

Author: impiyush83

concepts/temp.py

@@ -0,0 +1,44 @@
+
+
+
+
+def ans():
+    A = [1, 2, 2, 2, 4, 5, 6]
+    B = [3, 5]
+
+    def binarysearch(A, low, high, target):
+        if low <= high:
+            mid = (low + high) // 2
+
+            if target == A[mid]:
+                return mid
+            elif target < A[mid]:
+                return binarysearch(A, low, mid - 1, target)
+            else:
+                if target > A[mid - 1] and target < A[mid]:
+                    return mid + 1
+                elif target <= A[mid - 1]:
+                    return binarysearch(A, low, mid - 1, target)
+                else:
+                    return binarysearch(A, mid + 1, high, target)
+        return 0
+
+    lenA = len(A)
+
+    A = sorted(A)
+    B = sorted(B)
+
+    for item in B:
+        if item >= A[-1]:
+            yield lenA
+        elif item < A[0]:
+            yield 0
+        elif item == A[0]:
+            yield 1
+        else:
+            index = binarysearch(A, 0, len(A)-1, item)
+            yield len(A) - index
+
+
+for i in ans():
+    print(i)

concepts/walvet_tree.py

@@ -0,0 +1,87 @@
+from collections import  defaultdict
+
+class WaveletTree:
+    def __init__(self):
+        self.list = []
+        self.rank = []
+        self.left = None
+        self.right = None
+
+    def assign_ranks(self):
+        if not self.list:
+            return []
+        maxi = max(self.list)
+        mini = min(self.list)
+        mid = (maxi + mini) / 2
+        return [0 if item <= mid else 1 for item in self.list]
+
+def create_walvet_tree(_list):
+    _root = WaveletTree()
+    _root.list = _list
+    if len(_list) <= 1:
+        return _root
+
+    _root.rank = _root.assign_ranks()
+
+    right = []
+    left = []
+
+    for index in range(0, len(_root.rank)):
+        if _root.rank[index] == 1:
+            right.append(_root.list[index])
+        else:
+            left.append(_root.list[index])
+
+    _root.left = create_walvet_tree(left)
+    _root.right = create_walvet_tree(right)
+    return _root
+
+
+def inorder(_root):
+    if _root:
+        print(_root.list, _root.rank, _root.left, _root.right)
+        inorder(_root.left)
+        inorder(_root.right)
+
+
+def level_order(_root):
+
+    if not _root:
+        print("Empty tree")
+        return
+
+    dicto = defaultdict(lambda : [])
+
+    queue = [(_root, 0)]
+
+    while queue:
+        item, lvl = queue.pop(0)
+        if item == 'X':
+            continue
+        dicto[lvl].append(
+            "".join([str(item) for item in item.rank]) if item.rank else 'X'
+        )
+        queue.append((item.left if item.left else 'X', lvl + 1))
+        queue.append((item.right if item.left else 'X', lvl + 1))
+    return dicto
+
+
+def rqq(ksmallest, left, right):
+
+    pass
+
+
+print("Enter input list:")
+# input_list = list(set(map(int, input().split())))
+input_list = [6 , 2, 0 ,7 , 9, 3, 1 , 8 , 5, 4]
+root = create_walvet_tree(input_list)
+inorder(root)
+dicto = level_order(root)
+print(dicto)
+# print("RQQ inputs:")
+# k, l, r = list(map(int, input().split()))
+# rqq(k, l, r)
+
+
+
+