foo.cpp: In function 'int main()':
foo.cpp:11:15: error: 'getchar' was not declared in this scope
foo.cpp:21:15: error: 'getchar' was not declared in this scope
foo.cpp:81:17: error: 'putchar' was not declared in this scope
foo.cpp:7:17: warning: unused variable 't' [-Wunused-variable]