Compilare: main.cpp: In function 'void solve()': main.cpp:30:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(d=0; d<vec[i].size(); d++) ~^~~~~~~~~~~~~~ main.cpp:77:10: warning: statement has no effect [-Wunused-value] for(i; i>=0; i--) ^ main.cpp:66:20: warning: 'js' may be used uninitialized in this function [-Wmaybe-uninitialized] j_urm=j+dy[d]; ~^~~~~~ main.cpp:65:20: warning: 'is' may be used uninitialized in this function [-Wmaybe-uninitialized] i_urm=i+dx[d]; ~^~~~~~