Compilare: main.cpp: In function 'long long int dfs(int, int)': main.cpp:17:10: warning: statement has no effect [-Wunused-value] for(i; i<=k; ++i){ ^ main.cpp: In function 'int main()': main.cpp:31:11: warning: unused variable 'j' [-Wunused-variable] int i,j,c,f,x,y; ^ main.cpp:31:13: warning: unused variable 'c' [-Wunused-variable] int i,j,c,f,x,y; ^ main.cpp:32:8: warning: unused variable 'sum' [-Wunused-variable] ll sum=0,pr=1; ^~~ main.cpp:32:14: warning: unused variable 'pr' [-Wunused-variable] ll sum=0,pr=1; ^~