foo.cpp: In function 'int main()':
foo.cpp:48:23: error: 'printf' was not declared in this scope
    printf("Case #%d",i);printf(": Both\n");
                       ^
foo.cpp:52:23: error: 'printf' was not declared in this scope
    printf("Case #%d",i);printf(": Heap\n");
                       ^
foo.cpp:57:23: error: 'printf' was not declared in this scope
    printf("Case #%d",i);printf(": BST\n");
                       ^
foo.cpp:60:22: error: 'printf' was not declared in this scope
   printf("Case #%d",i);printf(": Neither\n");
                      ^
foo.cpp: In function 'bool check(int)':
foo.cpp:22:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
foo.cpp: In function 'bool check1(int)':
foo.cpp:38:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^