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:36:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i == word.size()) ~~^~~~~~~~~~~~~~ main.cpp:38:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if((i < word.size() && from <= n && s[from] < word[i]) || (from > n)) ~~^~~~~~~~~~~~~