Compilare: user.cpp: In function ‘int main()’: user.cpp:86:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < w[i].size(); j++){ ^ user.cpp: In function ‘int num()’: user.cpp:31:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(sir, 1, DIM, fin); ^ user.cpp:40:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(sir, 1, DIM, fin); ^ user.cpp: In function ‘int main()’: user.cpp:47:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(sir, 1, DIM, fin); ^