Compilare: user.cpp: In function ‘void prefibo(int)’: user.cpp:50:43: warning: operation on ‘k’ may be undefined [-Wsequence-point] fib[++k] = fib[k - 1] + fib[k - 2]; ^ user.cpp:50:43: warning: operation on ‘k’ may be undefined [-Wsequence-point] user.cpp:53:32: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘long long int’ [-Wformat=] printf("%d %d\n", k, fib[k]); ^ user.cpp:47:16: warning: unused variable ‘c’ [-Wunused-variable] int k = 2, c=0; ^ user.cpp: In function ‘int main()’: user.cpp:65:10: warning: unused variable ‘okb’ [-Wunused-variable] bool okb = 0; ^ user.cpp:69:9: warning: unused variable ‘k’ [-Wunused-variable] int k = 1; ^ user.cpp:63:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^