Compilare: main.cpp: In function 'long long int solve(std::vector<int>&, int)': main.cpp:70:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < arr.size(); ++i) ~~^~~~~~~~~~~~ main.cpp:79:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < arr.size(); ++i) { ~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:100:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("yamstp.in", "r", stdin); ^ main.cpp:101:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("yamstp.out", "w", stdout); ^