Compilare: user.cpp: In function ‘int main()’: user.cpp:25:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<n.size();i++)ans+=cst[n[i]-'0']; ^ user.cpp:30:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<n.size();i++)s[i]=s[i-1]+cst[n[i]-'0']; ^ user.cpp:35:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[i]-cst[n[i]-'0']+cst[j]+2*(n.size()-i-1)<=p){ ^