Compilare: main.c: In function 'main': main.c:42:30: warning: unused variable 'b' [-Wunused-variable] int N, A, B, C, i, n, a, b; ^ main.c:42:27: warning: unused variable 'a' [-Wunused-variable] int N, A, B, C, i, n, a, b; ^ main.c:42:24: warning: unused variable 'n' [-Wunused-variable] int N, A, B, C, i, n, a, b; ^ main.c:45:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d %d %d",&N, &A, &B, &C); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~