Compilare: main.cpp: In function 'void elimin(int)': main.cpp:70:42: warning: comparison of constant '-1' with boolean expression is always true [-Wbool-compare] if(it != father[nod] && used[it] != -1) ~~~~~~~~~^~~~~ main.cpp:67:9: warning: unused variable 'i' [-Wunused-variable] int i,vecin; ^ main.cpp:67:11: warning: unused variable 'vecin' [-Wunused-variable] int i,vecin; ^~~~~ main.cpp: In function 'int main()': main.cpp:76:11: warning: unused variable 'j' [-Wunused-variable] int i,j,x,y; ^ main.cpp: In function 'void buildLG()': main.cpp:22:15: warning: iteration 200008 invokes undefined behavior [-Waggressive-loop-optimizations] lg[i] = lg[i / 2] + 1; ~~~~~~^~~~~~~~~~~~~~~ main.cpp:21:23: note: within this loop for(int i = 2 ; i <= 2 * NMAX ; i++) ~~^~~~~~~~~~~