Calculate the number of string can be formed by this formula in one statement..
for cross check the result is 2N!/((N+1)! * N!).... where is number of A or B in string On Thu, Aug 5, 2010 at 8:54 AM, Ashish Goel <[email protected]> wrote: > >> >> void dyckWords(int index, int open, int close) >> { >> static int dyck=0; >> if (index == 2 *n) >> { >> printf("%s\n", out); >> return ; >> } >> >> out[index] = '('; //or A >> if ((open + 1) <= n && open >= close) >> >> >> >> { >> dyckWords(index + 1, open + 1, close); >> } >> out[index] = ')';//or B >> >> if ((close + 1) <= n && open >= close) >> { >> dyckWords(index + 1, open, close + 1); >> } >> } >> >> Best Regards >> Ashish Goel >> "Think positive and find fuel in failure" >> +919985813081 >> +919966006652 >> >> >> On Mon, Jul 19, 2010 at 1:25 AM, Amir hossein Shahriari < >> [email protected]> wrote: >> >>> @ashish: AAA is the prefix of the string and it is valid as a prefix and >>> it's only used for strings with length >= 6 (where it is a valid prefix) >>> actually only dp[i][j] where i==j counts the number of such strings and >>> otherwise there is no string where i!=j and it that case dp[i][j] counts the >>> number of valid prefixes for string >>> dp[0][0]=1 does satisfy both properties because 0=0 so the number of As & >>> Bs are the same >>> the logic behind n/2 is that if the length of the string is n this means >>> that it has n/2 As and n/2 Bs (n must be even) >>> the dp for n=4 doesn't look like that! this is how it looks (i just >>> compiled the code and checked values of dp): >>> 1 0 0 >>> 1 1 0 >>> 1 2 2 >>> so dp[2][2]=2 which means the number of strings with 2 As and 2 Bs is 2 >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Algorithm Geeks" group. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]<algogeeks%[email protected]> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/algogeeks?hl=en. >>> >> >> > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<algogeeks%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- Thanks & Regards Umesh kewat -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
