output of compilation with -g -O0

out: In function `_start':
(.text+0x0): multiple definition of `_start'
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 0 has invalid symbol index 10
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 1 has invalid symbol index 11
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 2 has invalid symbol index 2
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 3 has invalid symbol index 2
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 4 has invalid symbol index 10
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 5 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 6 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 7 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 8 has invalid symbol index 2
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 9 has invalid symbol index 2
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 10 has invalid symbol index 11
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 11 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 12 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 13 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 14 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 15 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 16 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 17 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 18 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 19 has invalid symbol index 12
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 20 has invalid symbol index 19
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_line): relocation 0 has invalid symbol index 2
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crt1.o:/build/buildd/eglibc-2.13/csu/../sysdeps/x86_64/elf/start.S:109: first defined here
out: In function `_fini':
(.fini+0x0): multiple definition of `_fini'
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crti.o:(.fini+0x0): first defined here
out:(.rodata+0x0): multiple definition of `_IO_stdin_used'
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crt1.o:(.rodata.cst4+0x0): first defined here
out: In function `__data_start':
(.data+0x0): multiple definition of `__data_start'
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crt1.o:(.data+0x0): first defined here
out: In function `__data_start':
(.data+0x8): multiple definition of `__dso_handle'
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/crtbegin.o:(.data+0x0): first defined here
out: In function `_init':
(.init+0x0): multiple definition of `_init'
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crti.o:(.init+0x0): first defined here
/tmp/ccPkESvh.o: In function `main':
main.cpp:(.text+0x0): multiple definition of `main'
out:(.text+0xe4): first defined here
/tmp/cc4xupU8.o: In function `random_products::random_products()':
random_products.cpp:(.text+0x0): multiple definition of `random_products::random_products()'
out:(.text+0x1f8): first defined here
/tmp/cc4xupU8.o: In function `random_products::search_AM(int const&, int const&)':
random_products.cpp:(.text+0x1d8): multiple definition of `random_products::search_AM(int const&, int const&)'
out:(.text+0x3d0): first defined here
/tmp/cc4xupU8.o: In function `random_products::get_AM()':
random_products.cpp:(.text+0x158): multiple definition of `random_products::get_AM()'
out:(.text+0x350): first defined here
/tmp/cc4xupU8.o: In function `random_products::get_probability()':
random_products.cpp:(.text+0x18e): multiple definition of `random_products::get_probability()'
out:(.text+0x386): first defined here
/tmp/cc4xupU8.o: In function `random_products::searchnreturn(int const&)':
random_products.cpp:(.text+0x240): multiple definition of `random_products::searchnreturn(int const&)'
out:(.text+0x438): first defined here
/tmp/cc4xupU8.o: In function `random_products::random_products()':
random_products.cpp:(.text+0x0): multiple definition of `random_products::random_products()'
out:(.text+0x1f8): first defined here
/tmp/cc4dQ3C0.o: In function `Student::Student(random_products&)':
student.cpp:(.text+0x0): multiple definition of `Student::Student(random_products&)'
out:(.text+0x510): first defined here
/tmp/cc4dQ3C0.o: In function `Student::print_student()':
student.cpp:(.text+0x9a): multiple definition of `Student::print_student()'
out:(.text+0x5aa): first defined here
/tmp/cc4dQ3C0.o: In function `Student::Student(random_products&)':
student.cpp:(.text+0x0): multiple definition of `Student::Student(random_products&)'
out:(.text+0x510): first defined here
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/crtend.o:(.dtors+0x0): multiple definition of `__DTOR_END__'
out:(.dtors+0x8): first defined here
/usr/bin/ld: error in out(.eh_frame); no .eh_frame_hdr table will be created.
collect2: ld returned 1 exit status