Find the missing permutation: Difference between revisions

Content added Content deleted

Inline

@@ Line 1: / Line 1: @@
 {{task}}
-These are all of the permutations of the symbols A, B, C and D,
-except for one that's not listed.
-Find that missing permutation.
-(cf. [[Permutations]])
-There is an obvious method :
-enumerating all permutations of A, B, C, D, and looking for the missing one.
+<pre>
-There is an alternate method.
+ABCD
-Hint : if all permutations were here,
-how many times would A appear in each position ?
-What is the parity of this number ?
-There is another alternate method.
-Hint: if you add up the letter values of each column, does a missing letter A, B, C, D
-from each column cause the total value for each column to be unique?
-<pre>ABCD
 CABD
 ACDB
@@ Line 40: / Line 24: @@
 CBDA
 DBCA
-DCAB</pre>
+DCAB
+</pre>
+Listed above are all of the permutations of the symbols &nbsp; '''A''', &nbsp; '''B''', &nbsp; '''C''', &nbsp; and &nbsp; '''D''', &nbsp; ''except'' &nbsp; for one permutation that's &nbsp; ''not'' &nbsp; listed.
+;Task:
+Find that missing permutation.
+;Methods:
+* Obvious method:
+         enumerate all permutations of   '''A''',  '''B''',  '''C''',  and  '''D''',
+         and then look for the missing permutation.
+* alternate method:
+         Hint:  if all permutations were shown above,  how many
+         times would  '''A'''  appear in each position?
+         What is the  ''parity''  of this number?
+* another alternate method:
+         Hint:  if you add up the letter values of each column,
+         does a missing letter   '''A''',  '''B''',  '''C''',  and  '''D'''   from each
+         column cause the total value for each column to be unique?
+;Related task:
+* &nbsp; [[Permutations]])
+<br><br>
 =={{header|360 Assembly}}==