Compilare: user.c: In function ‘main’: user.c:37:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.in","r",stdin),freopen("lanterna.out","w",stdout),scanf("%d%d",&n,&k); ^ user.c:37:42: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.in","r",stdin),freopen("lanterna.out","w",stdout),scanf("%d%d",&n,&k); ^ user.c:37:75: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.in","r",stdin),freopen("lanterna.out","w",stdout),scanf("%d%d",&n,&k); ^ user.c:39:12: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",e+i); ^ user.c:40:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); ^ user.c:45:12: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&i,&j),scanf("%d%d",&t[i][j],&w[i][j]),t[j][i]=t[i][j],w[j][i]=w[i][j]; ^ user.c:45:32: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&i,&j),scanf("%d%d",&t[i][j],&w[i][j]),t[j][i]=t[i][j],w[j][i]=w[i][j]; ^