Compilare: main.cpp: In function 'int main()': main.cpp:33:29: warning: unused variable 'next_node' [-Wunused-variable] unsigned int N, M, anc, a, next_node, c, d; ^~~~~~~~~ main.cpp:33:40: warning: unused variable 'c' [-Wunused-variable] unsigned int N, M, anc, a, next_node, c, d; ^ main.cpp:33:43: warning: unused variable 'd' [-Wunused-variable] unsigned int N, M, anc, a, next_node, c, d; ^