Compilare: user.cpp: In function ‘int main()’: user.cpp:42:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:44:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {fscanf(f,"%c",&c);for(j=1;j<=m;j++){fscanf(f,"%c",&c);a[i][j].c=c;}}//cout<<a[i][j].c<<" "; cout<<'\n';} ^ user.cpp:44:63: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {fscanf(f,"%c",&c);for(j=1;j<=m;j++){fscanf(f,"%c",&c);a[i][j].c=c;}}//cout<<a[i][j].c<<" "; cout<<'\n';} ^