Compilare: main.cpp: In function 'void read()': main.cpp:29:37: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized] G[y].push_back(make_pair(x, -c)); ^~ main.cpp:11:12: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized] int x, y, c, nr, cnt; ^ main.cpp:11:9: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized] int x, y, c, nr, cnt; ^