Add dynamic-programming module: ten classic DP problems, memoization vs tabulation vs space-optimised, call-count and pitfall transcripts (11 tests)

2026-11-09 08:41:01 +00:00
parent 911aef5515
commit cb1b28682f
33 changed files with 1551 additions and 0 deletions
@@ -0,0 +1,20 @@
+Longest Common Subsequence: "ABCBDAB" and "BDCABA"
+==================================================
+
+           -   B   D   C   A   B   A
+-          0   0   0   0   0   0   0
+A          0   0   0   0   1   1   1
+B          0   1   1   1   1   2   2
+C          0   1   1   2   2   2   2
+B          0   1   1   2   2   3   3
+D          0   1   2   2   2   3   3
+A          0   1   2   2   3   3   4
+B          0   1   2   2   3   4   4
+
+length (bottom-right cell)       = 4
+reconstructed from the full table = "BCBA"  (a valid subsequence of both strings)
+two-row version                   = 4  (length only; cannot rebuild the string)
+
+Calls made on two 15-character strings "ACGTTGCAACGTGCA" and "TGCATGCCGATGACG" (answer 9):
+   naive recursion -> 293086 calls
+   memoized        -> 247 calls