Compilare: user.cpp: In function ‘int main()’: user.cpp:69:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < Q[l].size(); j++) { ^ user.cpp: In function ‘void c(int&)’: user.cpp:24:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, bufsz, stdin); ^ user.cpp:34:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, bufsz, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:40:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inversari.in", "r", stdin); ^ user.cpp:41:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inversari.out", "w", stdout); ^ user.cpp:43:32: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, bufsz, stdin); ^