Compilare: user.c: In function ‘main’: user.c:47:53: warning: unused variable ‘j’ [-Wunused-variable] int a[15002], b[100002][4], c[15003]; int n, m, i, j; ^ user.c: In function ‘readfrom’: user.c:9:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d", n, m); ^~~~~~~~~~~~~~~~~~~~~~~~ user.c:11:3: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &a[i]); ^~~~~~~~~~~~~~~~~~~~~~ user.c:15:4: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &b[i][j]); ^~~~~~~~~~~~~~~~~~~~~~~~~