how to solve rubik's cube - kumaresh sa

8/6/2019 How to Solve Rubik's Cube - KUMARESH SA

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HOW TO SOLVE A RUBIK S CUBE

The Rubik's Cube is a 3-D mechanical puzzle invented by Ern Rubik in 1974. Rubik's Cube consist of six faces each covered by nine stickers, among six solid colours ( white, red, blue, orange, green, and yellow)Many methods are available to solve this cube. Here the simplest method is described.

In this method we use 7 algorithms and 7 steps to solve it. Here the algorithms:

1) Fi U Li Ui

2) Ri Di R D

3) U R Ui Ri Ui Fi U F

4) Ui Li U L U F Ui Fi

5) F R U Ri Ui Fi

6) R U Ri U R U U Ri

7) U R Ui Li U Ri Ui L

Where

F - Front clockwise turn

U - Upper clockwise turn

L - Left clockwise turn

R - Right clockwise turn

D - Down clockwise turn

Fi - Front inverse or anti-clockwise turn

Ui - Upper inverse or anti-clockwise turn

Li - Left inverse or anti-clockwise turn

Ri - Right inverse or anti-clockwise turn

Di - Down inverse or anti-clockwise turn
http://en.wikipedia.org/wiki/Three-dimensional_spacehttp://en.wikipedia.org/wiki/Mechanical_puzzlehttp://en.wikipedia.org/wiki/Ern%C5%91_Rubikhttp://en.wikipedia.org/wiki/Ern%C5%91_Rubikhttp://en.wikipedia.org/wiki/Ern%C5%91_Rubikhttp://en.wikipedia.org/wiki/Whitehttp://en.wikipedia.org/wiki/Redhttp://en.wikipedia.org/wiki/Bluehttp://en.wikipedia.org/wiki/Orange_%28colour%29http://en.wikipedia.org/wiki/Greenhttp://en.wikipedia.org/wiki/Yellowhttp://en.wikipedia.org/wiki/Yellowhttp://en.wikipedia.org/wiki/Greenhttp://en.wikipedia.org/wiki/Orange_%28colour%29http://en.wikipedia.org/wiki/Bluehttp://en.wikipedia.org/wiki/Redhttp://en.wikipedia.org/wiki/Whitehttp://en.wikipedia.org/wiki/Ern%C5%91_Rubikhttp://en.wikipedia.org/wiki/Mechanical_puzzlehttp://en.wikipedia.org/wiki/Three-dimensional_space


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DIAGRAMMATIC REPRESENTATION OF THE TURNS ARE GIVEN BELOW:


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STEP 1: (TO GET CROSS)

First step is to get cross at any one side of the cube as shown in fig (a) (here we have Red). For thatchoose any one color of your choice as center (here its red). Here we have four boxes (except center red) withred and other color combinations, such as Red-White, Red-Blue, Red-Yellow and Red-Green. Here we will solvefor Red-White, to get this Red-White in respective position (solved position i.e. in-between Red center andWhite center of the cube) just bring them exactly below to the respective position where it suppose to appear asshown in fig (a(i)). Then have two front turns to switch it to respective position. In some cases, we have Red-

White in respective position but not in correct orientation as in fig (a(ii)), so we use this algorithm Fi U Li Uifor flip purpose.

How to apply this algorithm: Apply this algorithm only once, when White in front side, Red in topside and Red-White not in correct orientation, as in the case of Red-White example. As default, color we chooseto form cross is the top side and the other color becomes the front side.

Thus Red-White is solved. Similarly we can solve other 3 combinations.

Note: Do not change the position of the cube until we finish a complete algorithm. Just apply the algorithm turns

without changing cubes position (i.e. Front as front, top as top and bottom as bottom we have only option to turn thesides, not to shift the sides).


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STEP 2: (TO SOLVE CORNER BOXES)

Now we will find in top Red layer except corner boxes others are solved i.e. cross. Now our job is to solve corner

boxes. Usually corner boxes have three different colors and always found in corners, bring these corner boxes (say Red-White-Green (RWG)) below to their respective position (where 3 colors of corner box coincide with 3 faces of the cube,

see fig(b(i)))and use this algorithm Ri Di R D repeatedly until its aligned to correct orientation.

How to apply this algorithm: Apply this algorithm when corner box is in lower right hand corner of

bottom layer (i.e. below the respective position) and this forms the front side of cube, here it is White and Redforms the top layer of the cube see fig (b(i)). Repeat the algorithm until we get the corner box oriented correctlyin the lower right hand corner of top layer .

Similarly solve the other 3 corner boxes. Now you can see top layer (here its Red) is completely solvedas shown in fig (b).

STEP 3: (RIGHT AND LEFT SHIFT)

So we solved top Red layer, next step is to solve middle layer. In this middle layer, we can find exceptcenter boxes all edge boxes are unsolved. So to solve this, turn the cube upside down so that your solved Redlayer becomes bottom layer and middle layer unchanged as shown in fig(c(i)). Now note the color of top layercenter one (here its Orange). Search for Non-Orange middle edge boxes in top layer, here we have middle edgeboxes as Green-Yellow, Yellow-Blue, Blue-White and White-Green . Lets have Green -Yellow (i.e. Green is


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adjacent to center Orange in top layer and Yellow in front or vice versa). Now all you need to do is bring thisGreen-Yellow to Yellow side of the cube (where the Yellow is centered) by turning the top layer alone such thatGreen-Yellow is placed over the centered Yellow as shown in fig(c(ii)). In case Yellow is adjacent to Orangeand Green in front, then bring it over Green side of the cube and place it over Green as shown in fig(c(iii)). Thekey idea is Non-Orange middle edge boxes in top layer have to be shifted to middle layer. There are two type of shift i.e. Right and Left shift. Right and Left shift are explained in fig (c(iv)) and fig (c(v)) respectively. For

Right shift, algorithm used is U R Ui Ri Ui Fi U F and for the Left shift it is Ui Li U L U F Ui Fi .

How to apply this algorithm: Apply this algorithm only once when the box to be shifted Right or Leftis in the front side of cube as shown in fig (iv).

Similarly we can solve other middle edge boxes with appropriate color boxes. By this method we can solveentire middle layer.


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STEP 4: (TO GET CROSS)

To solve the top layer we have to solve the cross of top layer first. We have 4 indicators to arrive at thecross. They are CENTER, INVERTED L ON LEFT CORNER , LINE and CROSS as shown in figure. We use

F R U Ri Ui Fi for this purpose. When we get center, apply the algorithm we will arrive at inverted L. Againapply the algorithm such that the inverted L is on the upper left hand corner of top layer as shown in figure, thenwe will arrive at central line. Again apply the algorithm such that the line is horizontal in top view, thus wearrive at cross at last. In some cases, after finishing step 3 we arrive at inverted L or line or cross instead of center, depending upon our luck which makes job easier.

How to apply this algorithm: 1) When we have a center in top layer, take it as top side and take anyside as front and apply this algorithm once.

2) When we have inverted L, choose a front side so that inverted L is onthe upper left hand corner of top layer and apply this algorithm once.

3) When we have line, choose a front side so that this line is horizontal intop view and apply this algorithm only once. In this case, we have 2 front sides choose any one of your choice.


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STEP 5: (TO GET MIDDLE ALIGN)

Here top layer middle edge box have to be aligned with corresponding colors in the middle and bottomlayer. By default, we have at least two middle edge boxes in top layer which will align automatically withcorresponding colors in the middle and bottom layer as we turn over the top layer alone. But there are 2 types init. 1) Two middle edge boxes that align automatically will be opposite to each other 2) Two middle edge boxes

that align automatically will be adjacent to each other. For both we use R U Ri U R U U Ri algorithm toalign all 4 middle edge boxes. Actually 1 st type is solved to get 2 nd type then by solving this we get all 4 middleedge boxes aligned.

How to apply the algorithm: For 1 st type, apply the algorithm only once when the automaticallyaligned top middle edge box is on the front side of the cube and other aligned middle edge box is on the back side of the cube.

For 2 nd type, apply the algorithm only once when the automaticallyaligned top middle edge box is on the right side of the cube and the other aligned middle edge box is on the back side of the cube.

STEP 6: (RESPECTIVE PLACE)

Finally we have 4 corner boxes left unsolved. To solve this we have to place the corresponding cornerbox in respective place (where corner boxs 3 colors matches with 3 faces of the cube in which corner box lies).

For this we use U R Ui Li U Ri Ui L algorithm.

How to apply the algorithm: 1) Usually we have at least one box in respective place. In this case we use thisalgorithm with this corner box in lower right hand corner of the top layer and apply this algorithm only once or twice. Andcheck for all corner boxes of top layer in their respective places after one complete algorithm is over. If not then do it

once again.

2) In some case, we could not find any corner boxes in respective places. Insuch case, we can apply algorithm from any corner boxes in lower right hand corner of the top layer. Make sure that we

should not use this algorithm more than twice. We will get all corner boxes in respective places irrespective of theirorientation (i.e., colors of the corner box doesnt coincide with its face but it contains the color) within 2 algorithms.

STEP 7: (ORIENTATION)

When we have all the 4 corner boxes in respective place but not in respective orientation then we have touse Ri Di R D algorithm for correct orientation.

How to apply this algorithm: A pply this algorithm with any one corner box, not in correct orientation inlower right hand corner of top layer and repeat the algorithm until we get one corner box oriented correctly in thelower right hand corner of top layer then just turn the top layer alone in anticlockwise direction so that anothercorner box with incorrect orientation will come to lower right hand corner of top layer. Now apply this algorithmagain until it gets oriented correctly. Repeat this procedure for all the corner boxes of top layer. Finally we havea solved Rubiks cube.

how to solve rubik's cube - kumaresh sa

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