Compilare: main.c: In function 'main': main.c:6:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("piramida.in","r",stdin),freopen("piramida.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:6:38: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("piramida.in","r",stdin),freopen("piramida.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:6:73: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("piramida.in","r",stdin),freopen("piramida.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~