Compilare: user.cpp: In function ‘void dfs(int, int, char*)’: user.cpp:47:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < v[ k ].size(); ++i ){ ^ user.cpp:40:12: warning: unused variable ‘ok’ [-Wunused-variable] int i, ok; ^ user.cpp:41:10: warning: unused variable ‘x’ [-Wunused-variable] char x; ^ user.cpp: In function ‘int main()’: user.cpp:65:15: warning: unused variable ‘j’ [-Wunused-variable] int n, i, j, t, d, x, y; ^ user.cpp:65:18: warning: unused variable ‘t’ [-Wunused-variable] int n, i, j, t, d, x, y; ^ user.cpp:65:21: warning: unused variable ‘d’ [-Wunused-variable] int n, i, j, t, d, x, y; ^