Compilare: main.cpp: In function 'int main()': main.cpp:63:15: warning: suggest parentheses around '-' inside '<<' [-Wparentheses] k = (1 << n - 1) - 1; ~~^~~ main.cpp:59:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("biti.in", "r", stdin); ^ main.cpp:60:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("biti.out", "w", stdout); ^ main.cpp:62:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^