Compilare: user.cpp: In function ‘void dfs(int, int, int, int)’: user.cpp:16:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) { ^ user.cpp:18:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[y].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:39:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[i].size();j++) { ^ user.cpp:26:13: warning: variable ‘k’ set but not used [-Wunused-but-set-variable] int i,j,k,x,y; ^ user.cpp: In function ‘void dfs(int, int, int, int)’: user.cpp:20:27: warning: ‘ny’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (nx!=tx&&ny!=ty&&nx!=ny&&s[v[x][i]]==s[v[y][j]]) ^