Compilare: main.cpp: In function 'long long int combinations(long long int, long long int)': main.cpp:14:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(n >= comb.size()) return 1e9; ~~^~~~~~~~~~~~~~ main.cpp:15:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(comb[n].size() > k) return comb[n][k]; ~~~~~~~~~~~~~~~^~~