Compilare: main.cpp: In function 'int main()': main.cpp:7:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fetite.in", "r", stdin); ^ main.cpp:8:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fetite.out", "w", stdout); ^ main.cpp:19:16: warning: 'R' may be used uninitialized in this function [-Wmaybe-uninitialized] cout << (N - R)*2 + 1; ~~~^~~~