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Ultimate challenge

mrCage

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Hi. Chris inspired me to come up with this variety of forced turn fewest moves challenge. Use this weeks challenge at http://fmc.mustcube.net and find a solution where exactly every second turn is a F turn. Noe tricks that i know will give a trivial solution based on a norm,al solution.

By the way the scramble is this one: D' F D F' L U F L' U2 B' D2 B' U' F' D' L D' F2 B L2 F2 R' L D' U F' B' L' R' F'

Per
 
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You *could* do your solution with F F2 F between every single move.
I don't know how something can done "between a single move", plus I think your idea violates the "where exactly every second turn is a F turn" requirement.

I'm sorry, I wasn't entirely clear. I meant you could do your normal solution, with F F2 F between every 2 moves. For example, for R U R', you would do R F F2 F U F F2 F R' F F2 F.

Why does it violate the "exactly every second turn is an F turn" requirement? I don't see how this implies other moves may not be F turns.
 

Tim Reynolds

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Why does it violate the "exactly every second turn is an F turn" requirement? I don't see how this implies other moves may not be F turns.

The word exactly used like that usually means something like if-and-only-if; that is, the moves that are F turns are exactly those that are every second turn.

Put another way: consider the algorithm F F F F F F F F. Is every second turn an F turn? Definitely. Is exactly every second turn an F turn? No, that is not an exact description of which turns are F turns; rather, every single turn is an F turn.
 

mrCage

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Noe tricks that i know will give a trivial solution based on a norm,al solution.
Here's one:

1. Replace every F* turn with (U D L2 R2 U' D') B* (U D L2 R2 U' D').
2. Separate the turns with F B F B F B2 F.

Ok ok!! Smartass:D I need to sharpen my formulation of the challenge.

Take the scramble of my first message in this thread and solve it with a sequence where exactly every second turn is exactly F and not F' or F2. Furthermore, the solution cannot also contain any subsequence that is an identity sequence - like for example F B F B F B2 F. Try to spoil this one Stefan:rolleyes:

Per
 

mrCage

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2x2 Block: B F R' F U F U' F D F D F B' F L2 F U' F U F U' F U F U2 F D' F

Per, what exactly is an identity sequence? A sequence which can simplify or a sequence which does nothing to the cube? For example F B' F, is that forbidden?

Yes, a sequence that does nothing to the cube (except possibly rotate centers ... )

Per
 

TMOY

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Well, here's my solution:
U' F B F L' F B F B2 F L F B F R': corner orientation
F B F L2 F B F R2 F B2 F U2: corner separation and xLL combined, 2 edges already solved
F B2 F L F B' F B2 F D': 3rd and 4th edge
F B2 F D F B2 F U2 F B2 F D: 5h edge
F D' F B2 F B' F R: 6th edge
F D2 F B F B F L F B2 F B2 F B2 F B F U2 F B2 F D F B F D2: 7th and 8th edge
F L F B2 F B" F D' F B2 F R2 F B2 F D F B2 F B2 F B2 F B F L': middle layer orientation
F B2 F D2 F U2 F B' F B2 F L2 F: middle layer permutation
 

TMOY

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Well, with CF it's really not very difficult once you master some little tricks for putting the F and B layers in the position you want :)
 
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mrCage

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