/tmp/ccKy85Jr.o: In function `main':
ex1.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccNfamoV.o:main.cpp:(.text.startup+0x0): first defined here
/tmp/ccNfamoV.o: In function `main':
main.cpp:(.text.startup+0x2b): undefined reference to `ex1_ordered_vector()'
main.cpp:(.text.startup+0x37): undefined reference to `ex1_ordered_queue()'
main.cpp:(.text.startup+0x3e): undefined reference to `ex1_reverse_array()'
main.cpp:(.text.startup+0x45): undefined reference to `ex1_reverse_vector()'
main.cpp:(.text.startup+0x4c): undefined reference to `ex1_reverse_stack()'
main.cpp:(.text.startup+0x53): undefined reference to `ex1_ordered_array()'
collect2: error: ld returned 1 exit status