can be solved easily if the elements of the array lie in a limited range
which can b known beforehand...!!
On Fri, May 27, 2011 at 2:10 PM, Aakash Johari <aakashj....@gmail.com>wrote:
> yes, you are right. map insertion takes O(log n) time. so if you know the
> upper bound of N, you can simply map the existence/non-existence of any
> particular element in an array. that will be in constant time (for query
> purposes) and O(n) time for preprocessing.
>
>
> On Fri, May 27, 2011 at 1:29 AM, sukhmeet singh <sukhmeet2...@gmail.com>wrote:
>
>> @Dave nd @Akash can u explain a bit more.. I didn't get what u say..
>> Inserting in a map takes O(log n) time !!
>>
>> On Fri, May 20, 2011 at 8:35 PM, Aakash Johari <aakashj....@gmail.com>wrote:
>>
>>> @Dave: This is what is still a doubt to me. I have searched but couldn't
>>> get the info regarding this.
>>>
>>>
>>> On Fri, May 20, 2011 at 8:01 AM, Dave <dave_and_da...@juno.com> wrote:
>>>
>>>> @Aakash: And tell me how map works. Is making an entry O(1) regardless
>>>> of the value of the entry? For example, is it O(n) to map the sequence
>>>> 1, 4, 9, 16, 25, ..., n^2?
>>>>
>>>> Dave
>>>>
>>>> On May 20, 9:39 am, Aakash Johari <aakashj....@gmail.com> wrote:
>>>> > @Dave: I got you. I will have to check before pushing the element in
>>>> map.
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > On Fri, May 20, 2011 at 7:30 AM, Dave <dave_and_da...@juno.com>
>>>> wrote:
>>>> > > @Aakash: Yeah, but try the same array with sum = 6 and see what
>>>> > > happens.
>>>> >
>>>> > > Dave
>>>> >
>>>> > > On May 20, 9:04 am, Aakash Johari <aakashj....@gmail.com> wrote:
>>>> > > > int main()
>>>> > > > {
>>>> > > > int a[10] = {5, 3, 10, 9, 8, 23, 11, 4, 12, 6};
>>>> > > > int i;
>>>> > > > int sum;
>>>> > > > int flag = 0;
>>>> >
>>>> > > > map<int, int> m;
>>>> >
>>>> > > > for ( i = 0; i < 10; i++ ) {
>>>> > > > m[a[i]] = 1;
>>>> > > > }
>>>> >
>>>> > > > sum = 13;
>>>> >
>>>> > > > for ( i = 0; i < 10; i++ ) {
>>>> > > > if ( m[sum - a[i]] == 1 ) {
>>>> > > > flag = 1;
>>>> > > > break;
>>>> > > > }
>>>> > > > }
>>>> >
>>>> > > > if ( flag == 1 )
>>>> > > > cout << a[i] << " " << sum - a[i] << endl;
>>>> >
>>>> > > > return 0;
>>>> >
>>>> > > > }
>>>> > > > On Fri, May 20, 2011 at 7:01 AM, hari <rajakin...@gmail.com>
>>>> wrote:
>>>> > > > > We can sort using STL sort function in main() before function
>>>> call of
>>>> > > > > arraysum().
>>>> >
>>>> > > > > On May 20, 6:49 am, Gunjan Sharma <gunjan.khan...@gmail.com>
>>>> wrote:
>>>> > > > > > First of all there is an infinite loop in this code....
>>>> > > > > > Secondly it works only for sorted array.
>>>> >
>>>> > > > > > On Fri, May 20, 2011 at 7:16 PM, hari <rajakin...@gmail.com>
>>>> wrote:
>>>> > > > > > > In while loop have i,j which points first and last index of
>>>> array.
>>>> > > In
>>>> > > > > > > while loop, Check the sum of a[i],a[j], If sum<k,increment i
>>>> or
>>>> > > else
>>>> > > > > > > decrement j. Run the while loop till i<j..
>>>> >
>>>> > > > > > > CODE:
>>>> >
>>>> > > > > > > int arraysum(int a[], int k, int i, int j)
>>>> > > > > > > while(i<j)
>>>> > > > > > > {
>>>> > > > > > > int p=0;
>>>> > > > > > > int b[10]; //to store index of selected nos
>>>> > > > > > > sum=a[i]+a[j];
>>>> > > > > > > if (sum==k)
>>>> > > > > > > {
>>>> > > > > > > b[p++]=i;b[p++]=j;
>>>> > > > > > > }
>>>> > > > > > > elseif(sum<k)
>>>> > > > > > > i++;
>>>> > > > > > > else(sum>k)
>>>> > > > > > > j++;
>>>> > > > > > > return b;
>>>> > > > > > > }
>>>> >
>>>> > > > > > > On May 20, 4:38 am, amit <amitthecoo...@gmail.com> wrote:
>>>> > > > > > > > given an array of integers, and an integer k, find out two
>>>> > > elements
>>>> > > > > > > > from the array whose sum is k in O(n) time. if no such
>>>> element
>>>> > > exists
>>>> > > > > > > > output none.
>>>> >
>>>> > > > > > > --
>>>> > > > > > > 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.
>>>> >
>>>> > > > > > --
>>>> > > > > > Regards
>>>> > > > > > Gunjan Sharma
>>>> > > > > > B.Tech IV year CSE
>>>> >
>>>> > > > > > Contact No- +91 9997767077
>>>> >
>>>> > > > > --
>>>> > > > > 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.
>>>> >
>>>> > > > --
>>>> > > > -Aakash Johari
>>>> > > > (IIIT Allahabad)- 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.
>>>> >
>>>> > --
>>>> > -Aakash Johari
>>>> > (IIIT Allahabad)- 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.
>>>>
>>>>
>>>
>>>
>>> --
>>> -Aakash Johari
>>> (IIIT Allahabad)
>>>
>>>
>>>
>>>
>>> --
>>> 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.
>>>
>>
>> --
>> 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.
>>
>
>
>
> --
> -Aakash Johari
> (IIIT Allahabad)
>
>
>
>
> --
> 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.
>
--
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.
