this program outputs life expectancy install: git clone https://github.com/itonyluke/life_expectancy life_expectancy compile: clang++ life_expectancy.cpp run: ./a.out built and tested on Darwin Kernel Version 18.7.0: Tue Jun 22 19:37:08 PDT 2021; root:xnu-4903.278.70~1/RELEASE_X86_64 x86_64