Compilare: user.c: In function ‘main’: user.c:36:1: warning: format ‘%lld’ expects argument of type ‘long long int’, but argument 3 has type ‘long int’ [-Wformat=] fprintf(file2, "%lld", expo(A, B, C)); // I added long long everywhere for 90 (4th attempt) ^ user.c:30:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &A); ^ user.c:31:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &B); ^ user.c:32:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &C); ^