Compilare: user.c: In function ‘main’: user.c:39:19: warning: unused variable ‘k’ [-Wunused-variable] int n, i, a, b, k; ^ user.c:40:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &n); ^ user.c:44:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &a, &b); ^