1 files changed, 112 insertions, 0 deletions
diff --git a/draft.py b/draft.py
new file mode 100755
index 0000000..f822362
--- /dev/null
+++ b/draft.py
@@ -0,0 +1,112 @@
+#!/usr/bin/python3
+
+import sys
+import heapq
+import collections
+import copy
+
+
+class BitRepr:
+    def __init__(self, x: int, length: int):
+        self.x = x
+        self.length = length
+
+    def add_zero(self):
+        self.x = self.x << 1
+        self.length += 1
+
+    def add_one(self):
+        self.x = self.x << 1
+        self.length += 1
+        self.x = self.x | 1
+
+    def __repr__(self):
+        return "{0:b}".format(self.x).zfill(self.length)
+
+
+class HuffmanNode:
+    def __init__(
+        self, occurence: int, is_leaf: bool,
+        symbol: int = None, left: 'HuffmanNode' = None, right: 'HuffmanNode' = None
+    ):
+        self.occurence = occurence
+        self.is_leaf = is_leaf
+        if is_leaf:
+            self.symbol = symbol
+        else:
+            self.left = left
+            self.right = right
+
+    @staticmethod
+    def leaf(occurence: int, symbol: int):
+        return HuffmanNode(occurence, is_leaf=True, symbol=symbol)
+
+    @staticmethod
+    def node(left: 'HuffmanNode', right: 'HuffmanNode'):
+        return HuffmanNode(left.occurence + right.occurence, is_leaf=False, left=left, right=right)
+
+    def __gt__(self, other: 'HuffmanNode') -> bool:
+        return self.occurence > other.occurence
+
+    def __lt__(self, other: 'HuffmanNode') -> bool:
+        return self.occurence < other.occurence
+
+    def __repr__(self) -> str:
+        if self.is_leaf:
+            return f"({self.symbol} {self.occurence})"
+        else:
+            return f"(NODE {self.occurence})"  # left {str(self.left)} right {str(self.right)})"
+
+    def put_tree(self, level: int = 0):
+        if self.is_leaf:
+            print(f"({self.symbol} {self.occurence})")
+            return
+        print(f"NODE {self.occurence}")
+        print(" " * level * 4, "left ", end="")
+        self.left.put_tree(level + 1)
+        print(" " * level * 4, "right ", end="")
+        self.right.put_tree(level + 1)
+
+    def to_bit_repr(self, parent_bits: 'BitRepr' = BitRepr(0, 0)) -> {int: 'BitRepr'}:
+        if self.is_leaf:
+            return {self.symbol: parent_bits}
+        left_bits = copy.deepcopy(parent_bits)
+        left_bits.add_zero()
+        right_bits = copy.deepcopy(parent_bits)
+        right_bits.add_one()
+        return {
+            **self.left.to_bit_repr(left_bits),
+            **self.right.to_bit_repr(right_bits)
+        }
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print("missing file name")
+        sys.exit(1)
+
+    file_name = sys.argv[1]
+    # print(file_name)
+
+    content = None
+    with open(file_name, "rb") as f:
+        content = f.read()
+    counter = collections.Counter(content)
+
+    huffman_nodes = [HuffmanNode.leaf(v, k) for k, v in dict(counter).items()]
+    heapq.heapify(huffman_nodes)
+
+    while len(huffman_nodes) >= 2:
+        # print(huffman_nodes)
+        left = heapq.heappop(huffman_nodes)
+        right = heapq.heappop(huffman_nodes)
+        node = HuffmanNode.node(left, right)
+        heapq.heappush(huffman_nodes, node)
+    # print(huffman_nodes)
+
+    huffman_tree = huffman_nodes[0]
+    huffman_tree.put_tree()
+    bit_repr = huffman_tree.to_bit_repr()
+    print(bit_repr)
+
+    huffman_content = ''.join([str(bit_repr[s]) for s in content])
+    print(huffman_content)