@Tushar: Either value of k will work. You are going to search both sides of k.
Dave On Aug 3, 10:59 pm, Tushar Bindal <tushicom...@gmail.com> wrote: > if we do not know k, how do we find it? > > inthe series : 17 15 13 11 9 1 3 5 7 > > we can take k at element 1 also as the descending series can be 17 15 13 11 > 9 1 and ascending 3 5 7 > OR > descending 17 15 13 11 9 and ascending 1 3 5 7 > isn't there any relationship in kth and (k+1)th element that helps us find > out k correctly > > On Thu, Aug 4, 2011 at 7:37 AM, Ankur Khurana <ankur.kkhur...@gmail.com>wrote: > > > > > > > For question two , > > try this. > > > see te element at arr[0] . and supose you have to find k . if arr[0]==k , > > then yes we found the element else see the diff betweem arr[0] and k. that > > will be minimum amount of steps needed to convert a[0] to k(let abs(a[0]-k) > > = p). then repeat the procedure again at the new element arr[p] untill you > > find the number of reach end of array...... > > > On Thu, Aug 4, 2011 at 6:59 AM, Dave <dave_and_da...@juno.com> wrote: > > >> @Amit: If k is not known, you can find it with another binary search. > > >> Dave > > >> On Aug 3, 3:02 pm, amit karmakar <amit.codenam...@gmail.com> wrote: > >> > I think for question 1, the value of k is not provided, right? > > >> > On Aug 4, 12:53 am, Ankur Garg <ankurga...@gmail.com> wrote: > > >> > > Dave's solution looks gud to me :) > > >> > > On Wed, Aug 3, 2011 at 3:52 PM, Ankur Garg <ankurga...@gmail.com> > >> wrote: > >> > > > Q1 can be looked as rotated sorted array...check whether the no is > >> less or > >> > > > greater than kth element ..if greater search using binary search > >> with low =0 > >> > > > high k-1 and if less earch in right with low=k+1 high =n; > > >> > > > q2) Dont know :( > > >> > > > On Wed, Aug 3, 2011 at 3:44 PM, Dave <dave_and_da...@juno.com> > >> wrote: > > >> > > >> @Tushar: For problem 1, do a binary search on elements 1 to k, and > >> if > >> > > >> no hit is found, do a binary search on elements k+1 to n. > > >> > > >> For problem 2, suppose that you are searching the given array for > >> the > >> > > >> number 2. The idea is to take big steps when you are far from the > >> > > >> target, and small steps when you are close. Start with i = 0. If > >> a[i] ! > >> > > >> = 2, then add abs(a[i]-2) to i and try again. This is because it > >> will > >> > > >> take at least abs(a[i]-2) steps to get to 2. > > >> > > >> In this case, i = 0 and a[0] = 6, so add 4 to i, getting 4. a[4] = > >> 4, > >> > > >> so add 2 to i, getting 6. a[6] = 3, so add 1. a[7] = 2. > > >> > > >> Dave > > >> > > >> On Aug 3, 2:09 pm, TUSHAR <tusharkanta.r...@gmail.com> wrote: > >> > > >> > 1. Given an array of n-elements ? the 1st k -elements are in > >> > > >> > descending order and k+1 to n elements are in > >> > > >> > ascending order. give an efficient algo for searching an > >> > > >> > element ? > > >> > > >> > 2. Given an array of n-elements ? each element in the array is > >> either > >> > > >> > same or less by 1 or larger by 1 from the > >> > > >> > previous element . give an efficient algo for searching an > >> > > >> > element ? > > >> > > >> > e.g : 6 6 6 5 4 4 3 2 3 4 3 4 ............ > > >> > > >> -- > >> > > >> You received this message because you are subscribed to the Google > >> Groups > >> > > >> "Algorithm Geeks" group. > >> > > >> To post to this group, send email to algogeeks@googlegroups.com. > >> > > >> To unsubscribe from this group, send email to > >> > > >> algogeeks+unsubscr...@googlegroups.com. > >> > > >> For more options, visit this group at > >> > > >>http://groups.google.com/group/algogeeks?hl=en.-Hide quoted text - > > >> > - Show quoted text - > > >> -- > >> You received this message because you are subscribed to the Google Groups > >> "Algorithm Geeks" group. > >> To post to this group, send email to algogeeks@googlegroups.com. > >> To unsubscribe from this group, send email to > >> algogeeks+unsubscr...@googlegroups.com. > >> For more options, visit this group at > >>http://groups.google.com/group/algogeeks?hl=en. > > > -- > > Ankur Khurana > > Computer Science > > Netaji Subhas Institute Of Technology > > Delhi. > > > -- > > You received this message because you are subscribed to the Google Groups > > "Algorithm Geeks" group. > > To post to this group, send email to algogeeks@googlegroups.com. > > To unsubscribe from this group, send email to > > algogeeks+unsubscr...@googlegroups.com. > > For more options, visit this group at > >http://groups.google.com/group/algogeeks?hl=en. > > -- > Tushar Bindal > Computer Engineering > Delhi College of Engineering > Mob: +919818442705 > E-Mail : tushicom...@gmail.com > Website:www.jugadengg.com- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. 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