foo.cpp: In function 'int main(int, char**)':
foo.cpp:30:64: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             while((pos = (int)start.find(key, pos)) != string::npos){
                                                                ^
foo.cpp:36:41: error: 'printf' was not declared in this scope
                      printf("%d\n", step);
                                         ^
foo.cpp:51:64: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             while((pos = (int)start.find(key, pos)) != string::npos){
                                                                ^
foo.cpp:57:41: error: 'printf' was not declared in this scope
                      printf("%d\n", step);
                                         ^