Compilare: main.cpp: In function 'void back(int)': main.cpp:12:6: warning: unused variable 'f' [-Wunused-variable] int f = 1; ^ main.cpp: In function 'int main()': main.cpp:43:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in", "r", stdin); ^ main.cpp:44:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.out", "w", stdout); ^ main.cpp:46:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^