langs a-z

Task/Longest-common-subsequence/BASIC/longest-common-subsequence.basic

@@ -0,0 +1,15 @@
+FUNCTION lcs$ (a$, b$)
+    IF LEN(a$) = 0 OR LEN(b$) = 0 THEN
+	lcs$ = ""
+    ELSEIF RIGHT$(a$, 1) = RIGHT$(b$, 1) THEN
+	lcs$ = lcs$(LEFT$(a$, LEN(a$) - 1), LEFT$(b$, LEN(b$) - 1)) + RIGHT$(a$, 1)
+    ELSE
+	x$ = lcs$(a$, LEFT$(b$, LEN(b$) - 1))
+	y$ = lcs$(LEFT$(a$, LEN(a$) - 1), b$)
+	IF LEN(x$) > LEN(y$) THEN
+		lcs$ = x$
+	ELSE
+		lcs$ = y$
+	END IF
+    END IF
+END FUNCTION