Compilare: main.c: In function 'main': main.c:22:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^~~~~~~~~~~~~~~~~~~ main.c:24:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &a); ^~~~~~~~~~~~~~~~~~~ main.c:25:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^~~~~~~~~~~~~~~~~~~ main.c:11:11: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized] return cmmdc(a, b-a); ^~~~~~~~~~~~~ main.c:17:5: note: 'b' was declared here int main(){ ^~~~