Compilare: user.cpp: In function ‘int solve(int)’: user.cpp:15:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();++i) ^ user.cpp:14:15: warning: unused variable ‘ans’ [-Wunused-variable] int cur=0,ans=0,mx=-inf; ^ user.cpp: In function ‘int main()’: user.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();++i) ^ user.cpp:91:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size() && s[i]>47 && s[i]<58){x=x*10+s[i]-48;++i;} ^ user.cpp:101:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size() && s[i]>47 && s[i]<58){x=x*10+s[i]-48;++i;} ^ user.cpp:109:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] sum=0;for(i=0;i<v[0].size();++i)sum+=v[0][i]; ^