Compilare: main.cpp: In function 'int main()': main.cpp:58:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[i].size(); ++j) ~^~~~~~~~~~~~ main.cpp:15:31: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ main.cpp:19:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &x); ^