Merge pull request #2563 from jeongoon/master

[ch-082/jeongoon] I think this is correct one {ch-2.go, Ch2PlanA.pm}

2 files changed, 31 insertions, 17 deletions

diff --git a/challenge-082/jeongoon/go/ch-2.go b/challenge-082/jeongoon/go/ch-2.go
index a0246c7b2e..4cca7b4a72 100644
--- a/challenge-082/jeongoon/go/ch-2.go
+++ b/challenge-082/jeongoon/go/ch-2.go
@@ -19,24 +19,28 @@ import (
 
 type MaybeIntereaved string
 
+type SavedPlace struct {
+	Apos int
+	Bpos int
+}
+
 func (C MaybeIntereaved) IsInterleavedFrom (A string, B string) bool {
 	Alen, Blen, Clen := len(A), len(B), len(C)
 	if Alen + Blen != Clen {
 		return false
 	}
 
-	Apin, Bpin := -1, -1 // if * >= 0, we have plan B
+	savedPos := []SavedPlace{}
+
 	checkingPlanB := false
 
 	for Ai, Bi, Ci := 0, 0, 0 ;; Ci = Ai + Bi {
 		if checkingPlanB {
-			if Bpin > -1 {
-				// note: it was A[Ai] == B[Bi] == C[Ci]
-				// and tried A already.
-				Bi = Bpin + 1
-				Ai = Apin
-				Apin, Bpin = -1, -1
-				checkingPlanB = false
+			if len( savedPos ) > 0 {
+				Ai = savedPos[0].Apos
+				Bi = savedPos[0].Bpos
+				savedPos = savedPos[1:]
+
 				Ci = Ai + Bi
 			} else {
 				// there is no plan B ...
@@ -56,14 +60,21 @@ func (C MaybeIntereaved) IsInterleavedFrom (A string, B string) bool {
 				continue
 			}
 		} else if Bi == Blen {
-			return A[Ai:] == string(C[Ci:])
+			if A[Ai:] == string(C[Ci:]) {
+				return true
+			} else {
+				checkingPlanB = true
+				continue
+			}
 		}
 		if A[Ai] == B[Bi] {
 			if A[Ai] != C[Ci] {
 				checkingPlanB = true
 			}  else {
 				// remember this node
-				Apin, Bpin = Ai, Bi
+				savedPos = append(
+					[]SavedPlace{ SavedPlace { Apos: Ai,
+						Bpos: (Bi+1) } }, savedPos...)
 				// try plan A first
 				Ai++
 			}
diff --git a/challenge-082/jeongoon/perl/Ch2PlanA.pm b/challenge-082/jeongoon/perl/Ch2PlanA.pm
index 398d48acf5..b85eff1b9c 100644
--- a/challenge-082/jeongoon/perl/Ch2PlanA.pm
+++ b/challenge-082/jeongoon/perl/Ch2PlanA.pm
@@ -26,8 +26,7 @@ sub isInterleaving ($$$) {
         if ( $checkingPlanB ) {
             last if @saved == 0; # there is no plan B ...
 
-            ( $Ai, $Bi ) = @saved;
-            @saved = ();
+            ( $Ai, $Bi ) = @{pop @saved};
             $checkingPlanB = 0; # reset status
         }
         $Ci = $Ai + $Bi;
@@ -45,16 +44,20 @@ sub isInterleaving ($$$) {
             }
         }
         elsif ( $Bi == $Blen ) { # used $B all
-            # but no need to check plan B
-            # just because we always take 'A' when we have to choose
-            $interleaved = ( substr $A, $Ai ) eq ( substr $C, $Ci )
+            if ( (substr $A, $Ai) eq (substr $C, $Ci) ) {
+                # and rest of A is same as rest of C
+                $interleaved = 1
+            }
+            else {
+                ( $checkingPlanB = 1, redo );
+            }
         }
         else {
             my ( $headA, $headB ) = ((substr $A, $Ai, 1), (substr $B, $Bi , 1));
             if ( $headA eq $headB ) {
                 if ( $headA eq ( substr $C, $Ci, 1 ) ) {
                     # save this place
-                    @saved = ( $Ai, ($Bi+1) );
+                    push @saved, [ $Ai, ($Bi+1) ];
                     # then try A (always) first for next case
                     ++$Ai
                 }
@@ -81,4 +84,4 @@ sub isInterleaving ($$$) {
     $interleaved
 }
 
-!"yes! no!";
+!!"yes! no!";