libz.so.1 error1

Hi 
i am new in building AOSP
since 2 days working on linux 64(ubuntu)
now after make -j4 got last part error:

/home/mshome/AOSP/prebuilts/gcc/linux-x86/host/i686-linux-glibc2.7-4.6/bin/../lib/gcc/i686-linux/4.6.x-google/../../../../i686-linux/bin/as: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory

Solution : 

Try to add the i386 arch to your package manager:
$ sudo dpkg --add-architecture i386
$ sudo apt-get update

then, install the following packages (source: official android web pages - I cannot insert the URL since I'm a new user  )
$ sudo apt-get install git gnupg flex bison gperf build-essential \
zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \
libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \
libgl1-mesa-dev g++-multilib mingw32 tofrodos \
python-markdown libxml2-utils xsltproc zlib1g-dev:i386

and create the following symbolic link:
$ sudo ln -s /usr/lib/i386-linux-gnu/mesa/libGL.so.1 /usr/lib/i386-linux-gnu/libGL.so

Then, you can recompile android and it should work.