Compilare: user.cpp: In function ‘int main()’: user.cpp:11:13: warning: unused variable ‘x’ [-Wunused-variable] int n,k,x,i,j; ^ user.cpp:18:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("deque.out", "w", stdout); ^ user.cpp:19:22: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, 13, fin); ^ user.cpp:28:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, 500000*7+5, fin); ^