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lecture_notes:04-22-2011

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lecture_notes:04-22-2011 [2011/06/09 23:39]
eyliaw [Searching]
lecture_notes:04-22-2011 [2011/06/10 00:16]
eyliaw [Searching]
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 C_X(a) is the number of characters lexicographically before a in X. C_X(a) is the number of characters lexicographically before a in X.
-   0 +   
-   G 1 +   ​L ​2 
-   ​L ​3 +   ​O ​3
-   ​O ​4+
 O_X(a,i) is the number of occurrences of a in B_X[0,i]. O_X(a,i) is the number of occurrences of a in B_X[0,i].
-^ B_X[0,​i] ​ ^ O_X(G,i) ^ O_X(L,i) ^ O_X(O,i) ^ +^ i ^ B_X[0,i] ^ O_X(G,i) ^ O_X(L,i) ^ O_X(O,i) ^ 
-| 1 L       ​| 0        | 1        | 0        |  +| 1        | 0        | 1        | 0        |  
-| 2 LO      | 0        | 1        | 1        |  +| 2 LO       ​| 0        | 1        | 1        |  
-| 3 LO$     ​| 0        | 1        | 1        |  +| 3 LO$      | 0        | 1        | 1        |  
-| 4 LO$O    | 0        | 1        | 2        |  +| 4 LO$O     ​| 0        | 1        | 2        |  
-| 5 LO$OO   ​| 0        | 1        | 3        |  +| 5 LO$OO    | 0        | 1        | 3        |  
-| 6 LO$OOG ​ | 1        | 1        | 3        |  +| 6 LO$OOG ​  ​| 1        | 1        | 3        |  
-| 7 LO$OOGG | 2        | 1        | 3        |  +| 7 LO$OOGG ​ | 2        | 1        | 3        |  
-    + 
-    +There are then two recursive formulas to find the start and end positions of a substring. 
 +   End R_(aW) = C(a) + O(a,R_(W) - 1) + 1 or 1 if W is the empty string 
 +   Start R-(aW) = C(a) + O(a,R-(W)) or (n - 1) if W is the empty string 
 +Where a is the first character and W is the word. 
 + 
 +To find the end position of the substring GO in 
lecture_notes/04-22-2011.txt · Last modified: 2015/08/09 23:06 by 212.129.31.47