Compilare: main.cpp: In function 'void combine(Node&, Node&, ld)': main.cpp:10:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < a.l.size ()) { ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:31:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("craciun.in", "r", stdin); freopen ("craciun.out", "w", stdout); ^ main.cpp:31:77: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("craciun.in", "r", stdin); freopen ("craciun.out", "w", stdout); ^