Compilare: main.cpp: In function 'void read()': main.cpp:39:37: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized] G[y].push_back(make_pair(x, -c)); ^~ main.cpp:17:12: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized] int x, y, c, nr, cnt = 0; ^ main.cpp:17:9: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized] int x, y, c, nr, cnt = 0; ^ main.cpp:35:27: warning: 'nr' may be used uninitialized in this function [-Wmaybe-uninitialized] cout << nr << " "; ^~~