Compilare: main.cpp: In function 'int cmp(int, int)': main.cpp:18:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<=s[y].size();i++) { ~^~~~~~~~~~~~~ main.cpp:21:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (nr==s[x].size()) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:33:59: warning: suggest parentheses around '&&' within '||' [-Wparentheses] if (s[i].size()>a.size() || s[i].size()==a.size() && s[i]<a) ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~