Add the section of hash algorithm. Refactor the section of hash map. (#555)

codes/python/chapter_hashing/simple_hash.py

@@ -0,0 +1,56 @@
+"""
+File: simple_hash.py
+Created Time: 2023-06-15
+Author: Krahets (krahets@163.com)
+"""
+
+
+def add_hash(key: str) -> int:
+    """加法哈希"""
+    hash = 0
+    modulus = 1000000007
+    for c in key:
+        hash += ord(c)
+    return hash % modulus
+
+
+def mul_hash(key: str) -> int:
+    """乘法哈希"""
+    hash = 0
+    modulus = 1000000007
+    for c in key:
+        hash = 31 * hash + ord(c)
+    return hash % modulus
+
+
+def xor_hash(key: str) -> int:
+    """异或哈希"""
+    hash = 0
+    modulus = 1000000007
+    for c in key:
+        hash ^= ord(c)
+    return hash % modulus
+
+
+def rot_hash(key: str) -> int:
+    """旋转哈希"""
+    hash = 0
+    modulus = 1000000007
+    for c in key:
+        hash = (hash << 4) ^ (hash >> 28) ^ ord(c)
+    return hash % modulus
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    hash = add_hash("Hello 算法")
+    print(f"加法哈希值为 {hash}")
+
+    hash = mul_hash("Hello 算法")
+    print(f"乘法哈希值为 {hash}")
+
+    hash = xor_hash("Hello 算法")
+    print(f"异或哈希值为 {hash}")
+
+    hash = rot_hash("Hello 算法")
+    print(f"旋转哈希值为 {hash}")