Compilare: user.cpp: In function ‘int main(int, char**)’: user.cpp:49:6: warning: unused variable ‘prev_k’ [-Wunused-variable] int prev_k = 30; ^ user.cpp:50:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(i, "%d\n", &T); ^ user.cpp:53:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(i, "%d %d\n", &N, &K); ^