From a3fa2828d999407b92b62f28916e9a93ee5831c3 Mon Sep 17 00:00:00 2001
From: Harry Stuart <42882697+harrystuart@users.noreply.github.com>
Date: Wed, 7 Dec 2022 18:09:43 +1100
Subject: [PATCH] Create normnumsum.py

---
 normnumsum.py | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 normnumsum.py

diff --git a/normnumsum.py b/normnumsum.py
new file mode 100644
index 0000000..99fb6d1
--- /dev/null
+++ b/normnumsum.py
@@ -0,0 +1,67 @@
+import numpy as np
+
+def find_longest_substring_slice(str1, str2, len_str1, len_str2):
+    num = np.zeros(shape=(len_str1, len_str2))
+
+    max_substring_len = 0
+    last_substring_begin = 0
+
+    for i in range(len_str1):
+        for j in range(len_str2):
+            # Extend substring
+            if str1[i] == str2[j]:
+                if i == 0 or j == 0:
+                    num[i][j] = 1
+                else:
+                    num[i][j] = 1 + num[i - 1][j - 1]
+
+                # Found new best substring
+                if num[i][j] > max_substring_len:
+                    max_substring_len = num[i][j]
+
+                    this_substring_begin = i - num[i][j] + 1
+
+                    if this_substring_begin != last_substring_begin:
+                        last_substring_begin = this_substring_begin
+
+    begin = last_substring_begin
+    end = last_substring_begin + max_substring_len - 1
+
+    return int(begin), int(end)
+
+def normnumsum(str1, str2):
+    str1 = str1.strip()
+    str2 = str2.strip()
+
+    len_str1 = len(str1)
+    len_str2 = len(str2)
+
+    if len_str1 > len_str2:
+        shorter_str = str2
+        len_shorter_str = len_str2
+        longer_str = str1
+        len_longer_str = len_str1
+    else:
+        shorter_str = str1
+        len_shorter_str = len_str1
+        longer_str = str2
+        len_longer_str = len_str2
+
+    num_substring_movements = 0
+
+    current_len_shorter_str = len_shorter_str
+
+    while current_len_shorter_str > 0:
+        substring_begin, substring_end = \
+            find_longest_substring_slice(shorter_str, longer_str, current_len_shorter_str, len_longer_str)
+
+        if substring_end <= 0:
+            num_substring_movements += len(shorter_str.replace(" ", ""))
+            break
+        else:
+            num_substring_movements += 1
+            shorter_str = (shorter_str[:substring_begin] + " " + shorter_str[substring_end + 1:]).strip()
+            current_len_shorter_str = len(shorter_str)
+
+    return num_substring_movements / len_shorter_str if num_substring_movements > 1 else 0
+