The source code of the leach is not found in that folder
Please define "that folder".
Please do not show text as black images !
I guess you know how to copy / paste a text ?
Besides that no LEACH was added to your shown ns-2.34/
Leach is a folder by name "mit/".
See leach+pegasis-ns234-files-2.tar.gz : Latest update >> No edits to be made.
.... is an old version, and an old text.