Help with AWK script. 1

[umcterp]

Given the following contents of a file how can I print all of it's contents and add a new line if the third fields name changes from the previous line?

Test a 400
Test a 400
Test b 500
Test b 500
Test c 502

Would like the output to look like the following.
Test a 400
Test a 400

Test b 500
Test b 500

Test c 502

 

[CaKiwi]

Try this

{
if (hld3 != $3) {
if (NR>1) print ""
hld3 = $3
}
print
}

CaKiwi

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