Shell Programming and Scripting

Hi,
I have a input file which contains following data

Code:

0 1
0 2
0 3
0 4
0 8 
0 9
0 11
1 1
1 2
1 6
1 7
1 8
1 9
2 1
2 11
2 12 
2 13

I would like to count a consecutive number in column 2 which are grouped by column 1 as well as obtain the maximum number of consecutive no. in each group.

So, results I want to get would be

Code:

0 4
0 2
0 1
1 2
1 4
2 1
2 3

As for maximum thing,

Code:

0 4
1 4
2 3

Thanks in advance

are you sure this isn't a homework?

That is a part of result which represents the stacking interaction in DNA. Column 1 represents time, Column 2 is residue in DNA participating stacking interaction. I just want to know the how many stacks are formed in a consecutive manner.
Since raw data is too complex to post here, I just omitted raw data and gave the example in order to explain more efficiently.

Try something like:

Code:

awk '$1>p || $2!=q+1{if(NR>1)print p,c; c=0} {p=$1; q=$2; c++} END{print p,c}' file

Thanks. It really works.

Also, I would appreciate it a lot if you reply me how to obtain maximum value in the group.

The result I would like to get is following

Code:

0 4
1 4
2 3

Try something like:

Code:

awk '$1>p || $2!=q+1{if(c>m)m=c; c=0} $1>p{if(NR>1)print p,m; m=0} {p=$1; q=$2; c++} END{if(c>m)m=c; print p,m}' file

Sincerely appreciate it !