The located assembly's manifest definition with name xxx.dll does not match the assembly reference

A client was getting this error on a set of ASP.NET pages when I sent them a new compiled DLL for the C# code-behind (ASP.NET 1.1), and I wasn't sure what was going on. I then noticed something in the stack trace which clued me in to what they were doing wrong:

Assembly Load Trace: The following information can be helpful to determine why the assembly 'xxxold' could not be loaded.


=== Pre-bind state information ===
LOG: DisplayName = xxxold
(Partial)
LOG: Appbase = file:///c:/inetpub/wwwroot/xxx
LOG: Initial PrivatePath = bin
Calling assembly : (Unknown).
===

It was the xxxold in there that tipped me off to what they had done wrong. Apparently, as a way to back up the old DLL before putting the new DLL in the ./bin folder, they just renamed the old one xxxold.dll, which causes C# to throw this error. If fact, after I tested it, any DLL that isn't explicitly referenced in the DLL will cause an error if it is placed in the ./bin folder. To fix the problem all I had the client do was rename the DLL xxx.old instead. This worked perfectly.

12 Coins Problem with Non-Adaptive Weighing

I recently came across a problem on the net which went as follow:

You are given 12 coins, one of which is defective. The defective coin is either lighter or heavier than the rest of the coins. You are given a balance scale and are told to determine which coin is defective by using three non-adaptive weighs. This means that you cannot change which coins you decide to weigh based on the any of the previous measurements. Meaning there is nothing like this allowed:

IF COIN X weighs the same as COIN Y
THEN WEIGH COIN Z against COIN W

Instead you must basically come up with your plan of attack before weighing any coins, and then not stray from that plan once you've started.

Here is the solution that I came up with:

KEY:
L - Left side
R - Right side
U - Unused
H - Heavy
F - Light

Notes:
When I write something like this:
{1 2 3 4 5 6 7 8}:{H F}

It means that the defective coin could be 1..8 and I don't know if it is Heavy or Light yet

When I write something like this:
{1}:{F}

It means that the defective coin is 1 and it is Light.

/************FIRST WEIGH******************************************/

L {1 2 3 4}     R {5 6 7 8}     U {9 10 11 12}

At this point:
     IF unbalanced THEN {1 2 3 4 5 6 7 8}:{H F}
     ELSE {9 10 11 12}:{H F}

/************SECOND WEIGH*****************************************/

L {6 2 10 12}     R {5 1 7 11}     U {3 4 8 9}

At this point:
     IF {1 2 3 4 5 6 7 8} THEN
          IF balanced THEN {3 4 8}:{H F}
          ELSE IF unbalanced and in the opposite position
               as the first weigh THEN {6 1}:{H F}
          ELSE IF unbalanced and in the same position
               as the first weigh THEN {5 2 7}:{H F}
     ELSE {9 10 11 12}
          IF balanced THEN {9}:{H F}
          ELSE {10 11 12}:{H F}

/************THIRD WEIGH******************************************/

L {7 3 9 10}     R {6 4 5 12}     U {1 11 2 8}

At this point:
     IF {6 1} THEN
          IF balanced
               IF R was light (second weigh) THEN {1}:{F}
               ELSE {1}:{H}
          ELSE
               IF R is light THEN {6}:{F}
               ELSE {6}:{H}
     IF {9} THEN
          IF L is light THEN {9}:{F}
          ELSE {9}:{H}
     IF {5 2 7} THEN
          IF balanced THEN
               IF L was light (second weigh) THEN {2}:{F}
               ELSE {2}:{H}
          ELSE
               IF R is heavy THEN
                    IF R was heavy (second weigh) THEN {5}:{H}
                    ELSE {7}:{F}
               ELSE
                    IF R was light (second weigh) THEN {5}:{F}
                    ELSE {7}:{H}
     IF {3 4 8} THEN
          IF balanced THEN
               IF R was light (first weigh) THEN {8}:{F}
               ELSE {8}:{H}
          ELSE
               IF L is heavy THEN
                    IF L was heavy (first weigh) THEN {3}:{H}
                    ELSE {4}:{H}
               ELSE
                    IF L was light (first weigh) THEN {3}:{F}
                    ELSE {4}:{F}
     If {10 11 12} THEN
          IF balanced THEN
               IF R was heavy (second weigh) THEN {11}:{H} ELSE {11}:{F}
          ELSE
               IF L is heavy THEN
                    IF L was heavy (second weigh) THEN {10}:{H}
                    ELSE {12}:{F}
               ELSE
                    IF L was light {second weight} THEN {10}:{F}
                    ELSE {12}:{H}

Retrieve Data from Either the Form or Querystring Object

This may have been known by everyone for quite some time now but it's news to me. Apparently in classic ASP there is an alternative to using Request.Form("key") and Request.QueryString("key"). Instead, Request("key") can be used which will check both the QueryString and the Form with one line of code. If a form value and a querystring value get sent over with the same key, I'm not sure which one take precedence though. If you feel like trying this experiment, please send me the results (I'm too lazy to try it myself).