Compilare: main.cpp: In function 'int check(int, const string&, const std::vector<char>&, int)': main.cpp:31:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < word.size() && from <= n && word[i] == s[from]) { ~~^~~~~~~~~~~~~ main.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(from > n && i < word.size()) ~~^~~~~~~~~~~~~ main.cpp:39:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < word.size() && word[i] < s[from]) ~~^~~~~~~~~~~~~ main.cpp:42:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i == word.size()) ~~^~~~~~~~~~~~~~ main.cpp:44:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < word.size() && word[i] > s[from]) ~~^~~~~~~~~~~~~ main.cpp:47:1: warning: control reaches end of non-void function [-Wreturn-type] } ^