Find max number of concurrent events - bash

Question

I'd like to print the max number of concurrent events given the start time and end time of each event in "hhmm" format (example input below)
$ cat input.txt
1030,1100
1032,1100
1032,1033
1033,1050
1034,1054
1039,1043
1040,1300
For this, I would
Sort by start time (column 1)
Use awk/sed to iterate over all values in column 2 (i.e end time) to find the count of end times preceeding this event which are greater than the current value (i.e find all
currently running events). To elaborate, assuming line 3 was being processed by awk ... Its end time is 10:33. The end times of the preceding 2 events are 11:00 and 11:00.
Since both these values are greater than 10:33 (i.e. they are still running at 10:33), the third column (i.e. number of concurrent jobs) would contain 2 for this line
The expected output of the awk script to find concurrent events for this input would be
0
1
2
2
2
4
0
Find the max value of this third column.
My awk is rudimentary at best and I am having difficulty implementing step 2.
I'd like this to be a pure script without resorting to a heavy weight language like java.
Hence any help from awk gurus would be highly appreciated. Any non-awk linux one liners are also most welcome.

Answer 1

BEGIN {FS="\,"; i=0}
{ superpos=0;
for (j=1; j<=i; j++ ){
if($2 < a[j,2])
++superpos
}
a[++i,1]=$1;
a[i,2]=$2;
print superpos;
a[i,3]=superpos;
}
END{ max=0;
for (j=1; j<=i; j++ ){
if ( a[j,3]>max)
max= a[j,3];
}
print "max = ",max;
}
Running at ideone
HTH!
Output:
0
0
2
2
2
4
0
max = 4
Edit
Or more awkish, if you prefer:
BEGIN {FS="\,"; max=0 }
{
b=0;
for (var in a){
if($2 < a[var]) b++;
}
a[NR]=$2;
print b;
if (b > max) max = b;
}
END { print "max = ", max }