Compilare: main.cpp: In function 'void add(int, int, int)': main.cpp:53:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = o; i <= a[no].size()-1; i += zeros(i)) ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'void solve(int)': main.cpp:90:34: warning: 'last' may be used uninitialized in this function [-Wmaybe-uninitialized] if(biff[o]==1) ga << last << "\n"; ^~~~