Compilare: main.cpp: In function 'int main()': main.cpp:54:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<prime.size() && 1LL*prime[i]*prime[i] <= x;i++) ~^~~~~~~~~~~~~ main.cpp:42:13: warning: unused variable 'j' [-Wunused-variable] int t,i,j; ^ main.cpp:43:11: warning: unused variable 'val1' [-Wunused-variable] int x,val1,val2; ^~~~ main.cpp:43:16: warning: unused variable 'val2' [-Wunused-variable] int x,val1,val2; ^~~~