/usr/bin/ld: /tmp/ccxZnZRV.o: in function `read_input()':
grader.cpp:(.text+0x0): multiple definition of `read_input()'; /tmp/cc4WRQqT.o:crocodile.cpp:(.text+0x0): first defined here
/usr/bin/ld: /tmp/ccxZnZRV.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc4WRQqT.o:crocodile.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cc4WRQqT.o: in function `main':
crocodile.cpp:(.text.startup+0x36): undefined reference to `travel_plan(int, int, int (*) [2], int*, int, int*)'
/usr/bin/ld: /tmp/ccxZnZRV.o: in function `main':
grader.cpp:(.text.startup+0x36): undefined reference to `travel_plan(int, int, int (*) [2], int*, int, int*)'
collect2: error: ld returned 1 exit status