topic Re: Counting groups of consecutive characters in string in SAS Programming

Counting groups of consecutive characters in string

mh04 — Thu, 30 Jul 2020 16:50:32 GMT

Hello,

I am working with strings made up of 0, 1, and 2 and for each string I need to:

Count how many groups of three consecutive 2s or more each string contains. For ID #1, it should identify three groups because there are three sequences of 2s containing at least three consecutive 2s; for ID #3 it should identify 0 groups. Groups containing more than three consecutive 2s should be counted only once. My code is counting all groups of three consecutive 2s, including within the same sequence...😑
Identify how long the longest sequence of consecutive 2s (made up of at least three consecutive 2s) is. For ID #1, it should look at all three sequences and identify that the longest equals 25; for ID #2, the longest sequence would be 11. I do have a clunky way of getting this – basically looking for the longest spell and working backwards – but I’d like to find a more efficient way of doing that.

ID	MONTHSTR
1	0000011220221000022222111111222222222220100022222222222222222222222220
2	22222222222000000222
3	2122
4	2220222022122221
5	11100000000000000101100000000000000000000
6	0022222222222222222
7	0022222222222222222
8	11100020002000222222222222222222222222222222222222222

I greatly appreciate any suggestion. Thanks!

Re: Counting groups of consecutive characters in string

PaigeMiller — Thu, 30 Jul 2020 17:19:00 GMT

data want;
	set have;
	sum=0;
	groups_of_3consec_twos=0;
	longest_string_of_twos=0;
	do i=1 to length(monthstr);
	    char=substr(monthstr,i,1);
		if char^=2 then sum=0;
		else sum=sum+1;
		if sum=3 then groups_of_3consec_twos = groups_of_3consec_twos+1;
		if sum>longest_string_of_twos then longest_string_of_twos=sum;
	end;
	drop i char sum;
run;

Re: Counting groups of consecutive characters in string

novinosrin — Thu, 30 Jul 2020 17:26:38 GMT



data have;
input ID MONTHSTR : $75.;
cards;
1

0000011220221000022222111111222222222220100022222222222222222222222220

2

22222222222000000222

3

2122

4

2220222022122221

5

11100000000000000101100000000000000000000

6

0022222222222222222

7

0022222222222222222

8

11100020002000222222222222222222222222222222222222222
;

data want;
 set have;
 want=0;
 do _n_=1 to countw(MONTHSTR,'2','k');
  want=sum(lengthn(scan(MONTHSTR,_n_,'2','k'))>=3,want);
 end;
run;

Re: Counting groups of consecutive characters in string

novinosrin — Thu, 30 Jul 2020 17:32:49 GMT

Forgot the longest in my previous-


data have;
input ID MONTHSTR : $75.;
cards;
1

0000011220221000022222111111222222222220100022222222222222222222222220

2

22222222222000000222

3

2122

4

2220222022122221

5

11100000000000000101100000000000000000000

6

0022222222222222222

7

0022222222222222222

8

11100020002000222222222222222222222222222222222222222
;

data want;
 set have;
 want=0;
 longest=0;
 do _iorc_=1 to countw(MONTHSTR,'2','k');
  _n_=lengthn(scan(MONTHSTR,_iorc_,'2','k'));
   want=sum(_n_>=3,want);
   longest=_n_<>longest;
 end;
run;

Re: Counting groups of consecutive characters in string

mh04 — Thu, 30 Jul 2020 17:43:43 GMT

Thank you!

Re: Counting groups of consecutive characters in string

mh04 — Thu, 30 Jul 2020 17:44:55 GMT

Thank you! You both make it look so easy...

Re: Counting groups of consecutive characters in string

smantha — Thu, 30 Jul 2020 17:54:18 GMT

data string;
informat string1 string2 string3 $100.;
infile cards dlm=',';
input string1 $ x $;

count=0;
max_len=0;
drop i string2 string3 len x;
if index(string1,'222') > 0 then do;
    string2 = translate(tranwrd(string1,'0','|'),'|','13456798 0');
	put string2=;
	do i = 1 to countc(string2,'|');
	     string3=scan(string2,i,'|');
		 put i= string3=;
		 len=length(compbl(strip(scan(string2,i,'|'))));
		 max_len=max(max_len,len);
		count=(len > 3) + count;
	end;
end;
cards;
0000011220221000022222111111222222222220100022222222222222222222222220,x
22222222222000000222,x
2122,x
2220222022122221,x 
11100000000000000101100000000000000000000,x 
0022222222222222222,x 
0022222222222222222,x 
11100020002000222222222222222222222222222222222222222,x 
;;;
run;