Compilare: main.cpp: In function 'long long unsigned int comb(int, int)': main.cpp:19:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<=n;i++) ~^~~ main.cpp:22:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i<=k) t=(t*i)%M; ~^~~ main.cpp:23:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i<=n-k) t=(t*i)%M; ~^~~~~