Compilare: user.cpp: In function ‘int main()’: user.cpp:17:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d%d%d",&N,&M,&Q); ^ user.cpp:21:63: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d",&mat[i][j]),p[++Size]={mat[i][j],i}; ^ user.cpp:27:50: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d",&v[i].first),v[i].second=i; ^