Compilare: main.cpp: In function 'void afis()': main.cpp:60:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<c2.size();i++) ~^~~~~~~~~~ main.cpp:66:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=where;i<c2.size();i++) ~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:115:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(nod[val[x1][y_1]].size()>mx) ~~~~~~~~~~~~~~~~~~~~~~~~^~~ main.cpp:120:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(nod[val[x2][y_2]].size()>mx) ~~~~~~~~~~~~~~~~~~~~~~~~^~~ main.cpp: In function 'void afis()': main.cpp:59:9: warning: 'where' may be used uninitialized in this function [-Wmaybe-uninitialized] int where; ^~~~~