Main.cc:14:16: warning: multi-character character constant [-Wmultichar] if(a[i][j]=='/0'){ ^~~~ Main.cc:22:16: warning: multi-character character constant [-Wmultichar] if(a[i][j]=='/0'){ ^~~~ Main.cc: In function ‘int main()’: Main.cc:5:7: error: ‘n’ was not declared in this scope cin>>n; ^