Compilare: user.c:41:6: warning: return type of ‘main’ is not ‘int’ [-Wmain] void main () ^ user.c: In function ‘main’: user.c:47:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.c:50:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&v[i][j]);}} ^