Longest common subsequence

Author: ratulb

codes/generate_docs

@@ -86,8 +86,9 @@ def update_index(
     print(new_entry)
 
     # Append new entry
-    index_lines.append(new_entry)
-    INDEX_MD.write_text(StringSlice("\n").join(index_lines) + "\n")
+    index_lines.append("\n"+ new_entry)
+    #INDEX_MD.write_text(StringSlice("\n").join(index_lines) + "\n")
+    INDEX_MD.write_text(StringSlice("\n").join(index_lines))
     print("Updated: ", INDEX_MD)
     print()
     print(INDEX_MD.read_text().splitlines()[-1])

codes/generate_docs.mojo

@@ -0,0 +1,38 @@
+### Longest Common Subsequence Recursive
+### Return the length of the longest common subsequence between two strings, or 0 if none exists
+
+
+fn longest_subseq(mut text1: String, mut text2: String) raises -> Int:
+    if len(text1) == 0 or len(text2) == 0:
+        return 0
+    if text1[len(text1) - 1] == text2[len(text2) - 1]:
+        text1 = text1[0:-1]
+        text2 = text2[0:-1]
+        return 1 + longest_subseq(text1, text2)
+    else:
+        text_1 = text1[0:-1]
+        text_2 = text2[0:-1]
+        count1 = longest_subseq(text1, text_2)
+        count2 = longest_subseq(text2, text_1)
+        return max(count1, count2)
+
+
+from testing import assert_equal
+
+
+fn main() raises:
+    var text1: String = "abcde"
+    var text2: String = "ace"
+    result = longest_subseq(text1, text2)
+    assert_equal(result, 3, "Assertion failed")
+
+    text1 = "abc"
+    text2 = "abc"
+    result = longest_subseq(text1, text2)
+    assert_equal(result, 3, "Assertion failed")
+
+    text1 = "abc"
+    text2 = "xyz"
+    result = longest_subseq(text1, text2)
+    assert_equal(result, 0, "Assertion failed")
+

codes/longest_common_subeq.mojo

@@ -48,3 +48,5 @@
 🟢 [Combination sum](combination_sum.md) ➔ Find all unique combinations of numbers from candidates (reusable unlimited times) that sum to target.
 
 🟢 [Word Search](wordsearch.md) ➔ Check if a word can be formed in a grid by sequentially adjacent (non-repeating) horizontal or vertical letters.
+
+🟢 [Longest Common Subsequence Recursive](longest_common_subeq.md) ➔ Return the length of the longest common subsequence between two strings, or 0 if none exists

docs/index.md

@@ -0,0 +1,45 @@
+### Longest Common Subsequence Recursive
+### Return the length of the longest common subsequence between two strings, or 0 if none exists
+
+```python
+
+
+fn longest_subseq(mut text1: String, mut text2: String) raises -> Int:
+    if len(text1) == 0 or len(text2) == 0:
+        return 0
+    if text1[len(text1) - 1] == text2[len(text2) - 1]:
+        text1 = text1[0:-1]
+        text2 = text2[0:-1]
+        return 1 + longest_subseq(text1, text2)
+    else:
+        text_1 = text1[0:-1]
+        text_2 = text2[0:-1]
+        count1 = longest_subseq(text1, text_2)
+        count2 = longest_subseq(text2, text_1)
+        return max(count1, count2)
+
+
+from testing import assert_equal
+
+
+fn main() raises:
+    var text1: String = "abcde"
+    var text2: String = "ace"
+    result = longest_subseq(text1, text2)
+    assert_equal(result, 3, "Assertion failed")
+
+    text1 = "abc"
+    text2 = "abc"
+    result = longest_subseq(text1, text2)
+    assert_equal(result, 3, "Assertion failed")
+
+    text1 = "abc"
+    text2 = "xyz"
+    result = longest_subseq(text1, text2)
+    assert_equal(result, 0, "Assertion failed")
+
+
+```
+
+
+[Source](https://github.com/ratulb/mojo_programming/blob/main/codes/longest_common_subeq.mojo)