Compilare: main.cpp: In function 'void read()': main.cpp:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(Min>st.size()) ~~~^~~~~~~~~~ main.cpp:14:11: warning: variable 'MinI' set but not used [-Wunused-but-set-variable] int i,MinI=0; ^~~~ main.cpp: In function 'bool solve(int)': main.cpp:35:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<a.size(); i++) ~^~~~~~~~~ main.cpp:43:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=len; j<a[i].size(); j++) ~^~~~~~~~~~~~