Compilare: user.cpp: In function ‘int main()’: user.cpp:42:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<s2.size(); i++) { ^ user.cpp:53:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = n1; i < s2.size(); i++) { ^ user.cpp:63:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++) { ^