Compilare: main.cpp: In function 'bool Hash_check(int)': main.cpp:14:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<Hash[y].size();++i) ~^~~~~~~~~~~~~~~ main.cpp: In function 'void Hash_del(int)': main.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<Hash[x%MOD].size();++i) ~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:48:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(op==3) ^