create flag for duplicate data by consideration of intermediate occurrence of same data

[Veeresh]

Help me on this below scenario.

output requirements

1)flag variable-  Flag on Countries IND and CHN. 

If country IND then for first occurrence its should flag as 1 and if same data available in next occurrence  that should flag it as 0  . 

If same data chain got dis continued then again if we find IND in country column again it flags first data occurrence as 1 and remain 0. 

Similarly 

If country CHN then for first occurrence its should flag as 0 , if same data available in next occurrence  that should flag it as 0  and only flag 1 for last occurrence of CHN before dis continue the same data .

If same data chain got dis continued then again if we find CHN in country column again it flags first data occurrence as 0 and next occurrence 1 . 

2)Count variable-  cumulative count .

data

Country

IND

IND

ENG

CHN

CHN

CHN

IND

IND

IND

USA

PAK

CHN

CHN

Expected output 

count Country FLAG
1          IND       1
1          IND       0
2          ENG     0
3          CHN     0
3          CHN     0
3          CHN     1
4          IND      1
4         IND       0
4         IND       0
5        USA       0
6        PAK       0
7       CHN       0
7       CHN      1

[ed_sas_member]

Hi @Veeresh 

Here is a way to do that:

data have;
	input Country $;
	datalines;
IND
IND
ENG
CHN
CHN
CHN
IND
IND
IND
USA
PAK
CHN
CHN
;

data want;
	set have;
	by country notsorted;
	
	if 		first.country and country = 'IND' then flag = 1;
	else if last.country and country = 'CHN' then flag = 1;
	else 	flag = 0;

	if first.country then count+1;
run;