foo.cc: In function 'int MoveRight(int, int, int, int*)':
foo.cc:25:2: warning: control reaches end of non-void function [-Wreturn-type]
  }
  ^
foo.cc: In function 'int main()':
foo.cc:8:9: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  int a[n];
         ^
/tmp/ccZATqB9.o: In function `main':
foo.cc:(.text.startup+0x91): undefined reference to `MoveRight(int, int, int*)'
foo.cc:(.text.startup+0xb2): undefined reference to `MoveRight(int, int, int*)'
collect2: error: ld returned 1 exit status

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。