memory.cpp: In function 'int main()':
memory.cpp:13:12: warning: unused variable 'it' [-Wunused-variable]
13 | for(auto it : v[i]){ cout << "faceup(" << i << ")" << endl; cin >> a; }
| ^~
/usr/bin/ld: /tmp/ccMzRwUC.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccJtQvTC.o:memory.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccMzRwUC.o: in function `main':
grader.cpp:(.text.startup+0x2f): undefined reference to `play()'
collect2: error: ld returned 1 exit status