Rotate the String

[gaurav gupta]

You are given an array with n elements { x₁, x₂ ... x_k ... x_n }, and K;

Rotate this string about K in O(n) time and constant space.

--
GAURAV GUPTA
B.Tech IV Yr. , Department of Computer Science & Engineering
IT BHU , Varanasi
Contacts
Phone No: +91-99569-49491

e-mail :
gaurav...@acm.org
gaurav.gu...@itbhu.ac.in

[Neeraj Singh]

On Sun, Aug 16, 2009 at 12:46 PM, gaurav gupta <1989....@googlemail.com> wrote:

You are given an array with n elements { x₁, x₂ ... x_k ... x_n }, and K;

Rotate this string about K in O(n) time and constant space.

what is the final array after rotation.

--
GAURAV GUPTA
B.Tech IV Yr. , Department of Computer Science & Engineering
IT BHU , Varanasi
Contacts
Phone No: +91-99569-49491

e-mail :
gaurav...@acm.org
gaurav.gu...@itbhu.ac.in

--
Neeraj Kumar
B.Tech (Part III)
Department of Computer Sc. & Engineering
IT-BHU,Varanasi

[Ajay]

three reverse are required for this.

1. Reverse the whole string.
2. Now count K from last.
3. Reverse the first half (1 to n-k+1)
4. reverse 2nd half (n-k+2 to n).

for Ex-

ABCDEF,  n=6
rotate around D (K=4)

• 1st rotation FEDCBA
• Pivot is 6-4+1=3
  
• Rev FED
• Rev CBA

You will get
DEFABC
thats what you want.

On Sun, Aug 16, 2009 at 12:46 PM, gaurav gupta <1989....@googlemail.com> wrote:

--
Ajay Kr. Gautam
Postgraduate Student,
Dept. of Computer Science & Engg., IT-BHU
Varanasi-221005, UP
India
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