Compilare: main.c: In function 'main': main.c:5:23: warning: variable 'file3' set but not used [-Wunused-but-set-variable] FILE *file1, *file2, *file3; ^~~~~ main.c:13:1: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &T); ^~~~~~~~~~~~~~~~~~~~~~~ main.c:17:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &N); ^~~~~~~~~~~~~~~~~~~~~~~