Compilare: user.cpp: In function 'void DFS(int)': user.cpp:16: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void constr()': user.cpp:31: warning: suggest parentheses around assignment used as truth value user.cpp: In function 'void dfs(int)': user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void solve()': user.cpp:70: warning: comparison between signed and unsigned integer expressions