Compilare: user.cpp: In function ‘int main()’: user.cpp:18:10: warning: statement has no effect [-Wunused-value] for(n;n>0;n--){ ^ user.cpp:24:21: warning: statement has no effect [-Wunused-value] for(elem;elem>0;elem--){ ^ user.cpp:30:21: warning: statement has no effect [-Wunused-value] for(elem;elem>0;elem--){ ^ user.cpp:17:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.cpp:19:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&op,&elem); ^