Compilare: main.cpp: In function 'void solve1(std::__cxx11::string)': main.cpp:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i64 i = 0; i < X.size(); ++i) ~~^~~~~~~~~~ main.cpp: In function 'i64 solve2(std::__cxx11::string)': main.cpp:24:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i64 i = 0; i < X.size(); ++i) { ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:34:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pixeli.in", "r", stdin); ^ main.cpp:35:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pixeli.out", "w", stdout); ^ main.cpp:36:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &n, &m); ^ main.cpp:38:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &op), cin>>crt; ^