Compilare: user.cpp: In function ‘bool get_and()’: user.cpp:52:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s[d].size() && s[d][i]=='&') ^ user.cpp: In function ‘bool get_xor()’: user.cpp:62:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s[d].size() && s[d][i]=='^') ^ user.cpp: In function ‘bool eval()’: user.cpp:72:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s[d].size() && s[d][i]=='|') ^ user.cpp: In function ‘int main()’: user.cpp:88:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<max(s[1].size(),s[2].size());++i) ^ user.cpp:90:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<s[1].size() && isalpha(s[1][i]) && !fol1[s[1][i]] && !fol2[s[1][i]]) ^ user.cpp:96:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(i< s[1].size() && isalpha(s[1][i]) && !fol1[s[1][i]]) ^ user.cpp:98:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<s[2].size() && isalpha(s[2][i]) && !fol2[s[2][i]] && !fol1[s[2][i]]) ^ user.cpp:104:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(i< s[2].size() && isalpha(s[2][i]) && !fol2[s[2][i]]) ^ user.cpp:110:34: warning: suggest parentheses around ‘+’ inside ‘<<’ [-Wparentheses] for(int per=0;per<(1<<cnt+1) && !okk;++per) ^