nile.cpp: In function 'int32_t main()':
nile.cpp:40:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
40 | freopen("v.inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
nile.cpp:41:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
41 | freopen("v.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccJjKip9.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cchbGAGc.o:nile.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccJjKip9.o: in function `main':
grader.cpp:(.text.startup+0x30e): undefined reference to `calculate_costs(std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status