Shell Programming and Scripting

Dear all,
I have file like below shown. In that file i need to identify how many state change in the column "type".For example 94713357873 goes from type B --> 1
i need to count it.But when we count the x number should be uniq, cant get the count B-->1 state chage for different x numbers.

so the result should be

x number state charge count ( B ---> 1)
===== ===============
94713357873 1
94713358041 2

Please help me do this.


x number y number type
========== ========== =====
94713357873 20080811101444 B
94713357873 20080811114146 B
94713357873 20080811133403 B
94713357873 20080811133528 B
94713357873 20080811133823 B
94713357873 20080811133947 1
94713357873 20080811220606 B
94713357873 20080811222120 B
94713357877 20080811185438 1
94713357879 20080811084432 1
94713358033 20080811205622 2
94713358035 20080811130731 1
94713358041 20080810230925 B
94713358041 20080810234013 1
94713358041 20080811181138 1
94713358041 20080810230925 B
94713358041 20080810234013 1
94713358041 20080811181138 1

Thank you.
Nayanajith.

Code:

#   awk '{if (t[$1]=="B" && $3==1){c[$1]+=1}t[$1]=$3}END{for (i in c) print i,c[i]}' file
94713358041 2
94713357873 1

more generic:

Code:

#  nawk 's[$1] == $3 {next} s[$1] == 0 { s[$1] = $3 ;  next } { c[$1  " " s[$1] "->" $3]++ ; s[$1] = $3 } END { for (i in c) { print i "  cnt=" c[i] } }' file | sort
94713357873 1->B  cnt=1
94713357873 B->1  cnt=1
94713358041 1->B  cnt=1
94713358041 B->1  cnt=2