Compilare: main.c: In function 'main': main.c:5:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("rfinv.in","r",stdin),freopen("rfinv.out","w",stdout),scanf("%d",&t); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:5:35: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("rfinv.in","r",stdin),freopen("rfinv.out","w",stdout),scanf("%d",&t); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:5:67: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("rfinv.in","r",stdin),freopen("rfinv.out","w",stdout),scanf("%d",&t); ^~~~~~~~~~~~~~ main.c:7:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~ main.c:9:13: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",a+i,b+i); ^~~~~~~~~~~~~~~~~~~~~ main.c:12:17: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&d[i][j]),c[i][j]=0; ^~~~~~~~~~~~~~~~~~~~