Compilare: main.cpp: In function 'int main()': main.cpp:54:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 1; sol.size() < n - 1; i++) ~~~~~~~~~~~^~~~~~~ main.cpp:42:15: warning: unused variable 'a' [-Wunused-variable] int n, m, a, b, cost = 0, i; ^ main.cpp:42:18: warning: unused variable 'b' [-Wunused-variable] int n, m, a, b, cost = 0, i; ^