Compilare: user.cpp: In function ‘void sol(int)’: user.cpp:12:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[x[i]].size();j++){ ^ user.cpp: In function ‘int main()’: user.cpp:52:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d%d",&n,&m,&d); ^ user.cpp:54:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&a); ^ user.cpp:56:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&b); ^