Compilare: user.cpp: In function ‘int main()’: user.cpp:57:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<f[i].size();j++){ ~^~~~~~~~~~~~ user.cpp:41:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&n); ^ user.cpp:62:17: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] fprintf (fout,"%d\n",s[k][s[k][1]+2]); ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~