Data update

Task/Longest-common-subsequence/PascalABC.NET/longest-common-subsequence.pas

@@ -0,0 +1,30 @@
+function Lengths(x,y: string): array[,] of integer;
+begin
+  var (m,n) := (x.Length,y.Length);
+  var C := new integer[m+1, n+1]; // filled with zeroes
+  for var i:=1 to m do
+  for var j:=1 to n do
+    if x[i] = y[j] then
+      C[i,j] := C[i-1,j-1] + 1
+    else C[i,j] := max(C[i,j-1], C[i-1,j]);
+  Result := C;
+end;
+
+function lcshelper(x,y: string; i,j: integer): string;
+begin
+  var C := Lengths(x,y);
+  if (i = 0) or (j = 0) then
+    Result := ''
+  else if  X[i] = Y[j] then
+    Result := lcshelper(X, Y, i-1, j-1) + X[i]
+  else if C[i,j-1] > C[i-1,j] then
+    Result := lcshelper(X, Y, i, j-1)
+  else Result := lcshelper(X, Y, i-1, j)
+end;
+
+function lcs(x,y: string) := lcshelper(x,y,x.Length,y.Length);
+
+begin
+  Println(lcs('1234','1224533324'));
+  Println(lcs('thisisatest','testing123testing'));
+end.