Compilare: user.cpp: In function ‘int comb(int, int)’: user.cpp:33:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = n-k+1; i <= n; i++) ^ user.cpp:35:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= k; i++) ^ user.cpp: In function ‘int main()’: user.cpp:57:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^