我在阅读 CYK算法 相关的内容,其中有一部分伪代码我无法理解。整个伪代码如下:
let the input be a string S consisting of n characters: a1 ... an.
let the grammar contain r nonterminal symbols R1 ... Rr.
This grammar contains the subset Rs which is the set of start symbols.
let P[n,n,r] be an array of booleans. Initialize all elements of P to false.
for each i = 1 to n
for each unit production Rj -> ai
set P[i,1,j] = true
for each i = 2 to n -- Length of span
for each j = 1 to n-i+1 -- Start of span
for each k = 1 to i-1 -- Partition of span
for each production RA -> RB RC
if P[j,k,B] and P[j+k,i-k,C] then set P[j,i,A] = true
if any of P[1,n,x] is true (x is iterated over the set s, where s are all the indices for Rs) then
S is member of language
else
S is not member of language
这些是我困惑的部分:
for each production RA -> RB RC
if P[j,k,B] and P[j+k,i-k,C] then set P[j,i,A] = true
请有人给一些关于这些伪代码的提示吗?