Compilare: main.cpp: In function 'int main()': main.cpp:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= n; i++){ ~~^~~~ main.cpp:9:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pufu.in", "r", stdin); ^ main.cpp:10:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pufu.out", "w", stdout); ^