Compilare: user.cpp: In function ‘int main()’: user.cpp:150:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < P[i].size() - 1; ++j) { ^ user.cpp:123:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rafaela.in", "r", stdin); ^ user.cpp:124:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rafaela.out", "w", stdout); ^