cave.cpp: In function 'void setIO(std::string)':
cave.cpp:20:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
20 | freopen((f+".in").c_str(),"r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cave.cpp:21:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
21 | freopen((f+".out").c_str(),"w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cc4pkKRR.o: in function `main':
cave.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc4l7heP.o:grader.c:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status