Compilare: user.cpp: In function ‘int main(int, char**)’: user.cpp:148:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<components.size(); ++i){ ^ user.cpp:149:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<components[i].size(); ++j){ ^ user.cpp:135:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in", "r", stdin); ^ user.cpp:136:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out", "w", stdout); ^ user.cpp:138:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:143:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^