cluedo.cpp: In function 'void usaco(std::string)':
cluedo.cpp:18:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
18 | freopen((s + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cluedo.cpp:19:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
19 | freopen((s + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccaPo8jo.o: in function `main':
grader.c:(.text.startup+0x0): multiple definition of `main'; /tmp/ccKGZVMl.o:cluedo.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccaPo8jo.o: in function `main':
grader.c:(.text.startup+0x49): undefined reference to `Solve()'
collect2: error: ld returned 1 exit status